Treatment for chronic low back pain: the focus should change to multimodal management that reflects the underlying pain mechanisms

Evaluating the Efficacy of Capacitive Resistive Monopolar Radiofrequency Combined With Proprioceptive Neuromuscular Facilitation in Managing Chronic Low Back Pain: A Randomised Controlled Trial

BACKGROUND AND PURPOSE

This randomised controlled trial evaluates the effectiveness of capacitive resistive monopolar radiofrequency (CRMRF) combined with proprioceptive neuromuscular facilitation (PNF) training in managing chronic low back pain (CLBP). Given the multifactorial nature of CLBP, this study explores a multimodal treatment approach integrating CRMRF, known for its thermal effects and ability to alleviate pain through improved cell metabolism and microcirculation, with PNF training, which enhances muscle strength, flexibility, and proprioception.

METHODS

This study was designed as a single-blind, parallel, randomised controlled trial conducted in an outpatient clinical setting. Over the course of four months, 62 participants, suffering from chronic low back pain were randomly assigned to receive either the combined CRMRF and PNF treatment or PNF alone, with primary outcomes measured in terms of pain and functional disability using the Visual Analogue Scale (VAS), Oswestry Disability Index (ODI). For secondary outcome of disability associated with pain, Quebec Pain Disability Scale (QPDS) and Roland-Morris Disability Questionnaire (RMDQ) were used. The study's hypothesis was that the combined treatment would reduce pain and disability more effectively than PNF alone.

RESULTS

Results indicated that the experimental group experienced greater improvements in pain and functional disability, surpassing the minimally clinically important difference (MCID) for the VAS, ODI, QPDS and RMDQ, suggesting the clinical relevance of the combined CRMRF and PNF approach.

DISCUSSION

These findings are consistent with previous research highlighting the benefits of CRMRF in various musculoskeletal disorders and suggest that integrating CRMRF with PNF training offers a promising non-invasive treatment option for CLBP sufferers. Overall, our study contributes to the growing evidence base supporting innovative, multimodal treatment strategies for managing CLBP, with the potential to enhance patients' quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05682287.

["Mixed pain": Current conceptualization and approach for Primary Care]

Despite being referenced in the literature for over a decade, the term "mixed pain" has hardly been formally defined. The strict binary classification of pain as purely neuropathic or nociceptive left a good proportion of patients unclassified; even the introduction of the term "nociplastic pain" in the International Association for the Study of Pain terminology leaves out patients who clinically present with a substantial overlap of nociceptive, neuropathic, and nociplastic symptoms. For these patients the term "mixed pain" is becoming increasingly recognized and accepted by the scientific community. This narrative review summarizes the highlights of mixed pain and emphasizes the importance of recognizing this type of pain in clinical practice.

Normality analysis of numeric rating scale scores in patients with chronic axial spine pain before and after medial branch blocks: a multicenter study

OBJECTIVE

The statistical analysis typically used to compare pain before and after interventions assumes that scores are normally distributed. The present study evaluates whether numeric rating scale (NRS) scores, specifically NRS-11 scores, are indeed normally distributed in a clinically relevant cohort of adults with chronic axial spine pain before and after analgesic intervention.

METHODS

Retrospective review from 4 academic medical centers of prospectively collected data from a uniform pain diary administered to consecutive patients after they had undergone medial branch blocks. The pain diary assessed NRS-11 scores immediately before injection and at 12 different time points after injection up to 48 hours. D'Agostino-Pearson tests were used to test normality at all time points.

RESULTS

One hundred fifty pain diaries were reviewed, and despite normally distributed pre-injection NRS-11 scores (K2 = 0.655, P = .72), all post-injection NRS-11 data were not normally distributed (K2 = 9.70- 17.62, P = .0001-.008).

CONCLUSIONS

Although the results of parametric analyses of NRS-11 scores are commonly reported in pain research, some properties of the NRS-11 do not satisfy the assumptions required for these analyses. The data demonstrate non-normal distributions in post-intervention NRS-11 scores, thereby violating a key requisite for parametric analysis. We urge pain researchers to consider appropriate statistical analysis and reporting for non-normally distributed NRS-11 scores to ensure accurate interpretation and communication of these data. Practicing pain physicians should similarly recognize that parametric post-intervention pain score statistics might not accurately describe the data and should expect articles to utilize measures of normality to justify the selected statistical methods.

Heterogeneity in response to treatment across tinnitus phenotypes

The clinical heterogeneity of chronic tinnitus poses major challenges to patient management and prompts the identification of distinct patient subgroups (or phenotypes) that respond more predictable to a particular treatment. We model heterogeneity in treatment response among phenotypes of tinnitus patients concerning their change in self-reported health burden, psychological characteristics, and tinnitus characteristics. Before and after a 7-day multimodal treatment, 989 tinnitus patients completed 14 assessment questionnaires, from which 64 variables measured general tinnitus characteristics, quality of life, pain experiences, somatic expressions, affective symptoms, tinnitus-related distress, internal resources, and perceived stress. Our approach encompasses mechanisms for patient phenotyping, visualizations of the phenotypes and their change with treatment in a projected space, and the extraction of patient subgroups based on their change with treatment. On average, all four distinct phenotypes identified at the pre-intervention baseline showed improved values for nearly all the considered variables following the intervention. However, a considerable intra-phenotype heterogeneity was noted. Five clusters of change reflected variations in the observed improvements among individuals. These patterns of treatment effects were identified to be associated with baseline phenotypes. Our exploratory approach establishes a groundwork for future studies incorporating control groups to pinpoint patient subgroups that are more likely to benefit from specific treatments. This strategy not only has the potential to advance personalized medicine but can also be extended to a broader spectrum of patients with various chronic conditions.

Exercise Training for Chronic Pain: Available Evidence, Current Recommendations, and Potential Mechanisms

Chronic pain conditions pose a significant global burden of disability, with epidemiological data indicating a rising incidence. Exercise training is commonly recommended as a standalone or complementary approach for managing various chronic pain conditions like low back pain, osteoarthritis, rheumatoid arthritis, fibromyalgia syndrome, and neuropathic pain. Regardless of the specific condition or underlying cause (e.g., autoimmune disease, chronic inflammation), exercise training consistently leads to moderate to large reductions in pain. Moreover, exercise yields numerous benefits beyond pain alleviation, including small-to-moderate improvements in disability, quality of life, and physical function. Despite its efficacy, there is a lack of comprehensive research delineating the optimal intensity, duration, and type of exercise for maximal benefits; however, evidence suggests that sustained engagement in regular exercise or physical activity is necessary to achieve and maintain reductions in both clinical pain intensity ratings and the level that pain interferes with activities of daily living. Additionally, the precise mechanisms through which exercise mitigates pain remain poorly understood and likely vary based on the pathophysiological mechanisms underlying each condition.

Critical Appraisal of Current Acute LBP Management and the Role of a Multimodal Analgesia: A Narrative Review

Acute low back pain (LBP) stands as a leading cause of activity limitation and work absenteeism, and its associated healthcare expenditures are expected to become substantial when acute LBP develops into a chronic and even refractory condition. Therefore, early intervention is crucial to prevent progression to chronic pain, for which the management is particularly challenging and the most effective pharmacological therapy is still controversial. Current guideline treatment recommendations vary and are mostly driven by expertise with opinion differing across different interventions. Thus, it is difficult to formulate evidence-based guidance when the relatively few randomized clinical trials have explored the diagnosis and management of LBP while employing different selection criteria, statistical analyses, and outcome measurements. This narrative review aims to provide a critical appraisal of current acute LBP management by discussing the unmet needs and areas of improvement from bench-to-bedside, and proposes multimodal analgesia as the way forward to attain an effective and prolonged pain relief and functional recovery in patients with acute LBP.

Effectiveness of patient education plus motor control exercise versus patient education alone versus motor control exercise alone for rural community-dwelling adults with chronic low back pain: a randomised clinical trial

BACKGROUND

Chronic low back pain (CLBP) is a common health problem in rural Nigeria but access to rehabilitation is limited. Current clinical guidelines unanimously recommend patient education (PE) including instruction on self-management, and exercises as frontline interventions for CLBP. However, the specific content of these interventions and how they are best delivered remain to be well-described, particularly for low-resource communities. This study determined the effectiveness of PE plus motor control exercise (MCE) compared with either therapy alone among rural community-dwelling adults with CLBP.

METHODS

A single-blind, three-arm parallel-group, randomised clinical trial including 120 adult rural dwellers (mean [SD] age, 46.0 [14.7] years) with CLBP assigned to PE plus MCE group (n = 40), PE group (n = 40), and MCE group (n = 40) was conducted. The PE was administered once weekly and the MCE twice weekly. Each group also received stretching and aerobic exercises twice weekly. All interventions were administered for 8 weeks. Blinded assessments for pain intensity and disability level as primary outcomes, and quality of life, global perceived recovery, fear-avoidance beliefs, pain catastrophising, back pain consequences belief and pain medication use as secondary outcomes were conducted at baseline, 8-week (immediately after intervention) and 20-week follow-ups.

RESULTS

All the groups showed significant improvements in all the primary and secondary outcomes evaluated over time. Compared with PE alone, the PE plus MCE showed a significantly greater reduction in pain intensity by an additional -1.15 (95% confidence interval [CI], -2.04 to -0.25) points at the 8-week follow-up and -1.25 (95% CI, -2.14 to -0.35) points at the 20-week follow-up. For disability level, both PE plus MCE and MCE alone showed a significantly greater improvement compared with PE alone by an additional -5.04% (95% CI, -9.57 to -0.52) and 5.68% (95% CI, 1.15 to 10.2) points, respectively, at the 8-week follow-up, and -5.96% (95% CI, -9.84 to -2.07) and 6.57% (95% CI, 2.69 to 10.4) points, respectively, at the 20-week follow-up. For the secondary outcomes, at the 8-week follow-up, PE plus MCE showed a significantly greater reduction in fear-avoidance beliefs about physical activity compared with either therapy alone, and a significantly greater reduction in pain medication use compared with PE alone. However, compared with PE plus MCE, PE alone showed a significantly greater reduction in pain catastrophising at all follow-up time points, and a significantly greater improvement in back pain consequences belief at the 20-week follow-up. Additionally, PE alone compared with MCE alone showed a significantly greater improvement in back pain consequences belief at all follow-up time points. No significant between-group difference was found for other secondary outcomes.

CONCLUSIONS

Among rural community-dwelling adults with CLBP, PE plus MCE led to greater short-term improvements in pain and disability compared with PE alone, although all intervention strategies were associated with improvements in these outcomes. This trial provides additional support for combining PE with MCE, as recommended in current clinical guidelines, to promote self-management and reduce the burden of CLBP in low-resource rural communities.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03393104), Registered on 08/01/2018.

Mobility Analysis of the Lumbar Spine with a Dynamic Spine-Correction Device

According to data, 60-70% of the world's population experience low-back pain (LBP) at least once during their lifetime, often at a young or middle age. Those affected are at risk of having worse quality of life, more missed days at work, and higher medical care costs. We present a new rehabilitation method that helps collect and analyze data on an ongoing basis and offers a more personalized therapeutic approach. This method involves assessing lumbar spine rotation (L1-L5) during torso movement using an innovative dynamic spine correction (DSC) device designed for postural neuromuscular reeducation in LBP. Spinal mobility was tested in 54 patients (aged 18 to 40 years) without LBP. Measurements were made with 12-bit rotary position sensors (AS5304) of the DSC device. During exercise, the mean lumbar spine rotation to the right was greater (4.78° ± 2.24°) than that to the left (2.99° ± 1.44°; p < 0.001). Similarly, the maximum rotation to the right was greater (11.35° ± 3.33°) than that to the left (7.42° ± 1.44°; p < 0.0001). The measurements obtained in the study can serve as a reference for future therapeutic use of the device.

Endplate role in the degenerative disc disease: A brief review

The degenerative disease of the intervertebral disc is nowadays an important health problem, which has still not been understood and solved adequately. The vertebral endplate is regarded as one of the vital elements in the structure of the intervertebral disc. Its constituent cells, the chondrocytes in the endplate, may also be involved in the process of the intervertebral disc degeneration and their role is central both under physiological and pathological conditions. They main functions include a role in homeostasis of the extracellular environment of the intervertebral disc, metabolic support and nutrition of the discal nucleus and annulus beneath and the preservation of the extracellular matrix. Therefore, it is understandable that the cells in the endplate have been in the centre of research from several viewpoints, such as development, degeneration and growth, reparation and remodelling, as well as treatment strategies. In this article, we briefly review the importance of vertebral endplate, which are often overlooked, in the intervertebral disc degeneration.

Chronic pain domains and their relationship to personality, abilities, and brain networks

Chronic pain is a multidimensional pathological state. Recent evidence suggests that specific brain properties and patients' psychological and physical traits are distorted in chronic pain patients. However, the relationship between these alterations and pain dimensions remains poorly understood. Here, we first evaluated multiple dimensions of chronic pain by assessing a broad battery of pain-related questionnaire scores (23 outcomes) of 107 chronic low back pain patients and identified 3 distinct chronic pain domains: magnitude, affect & disability, and quality. Second, we investigated the pain domains relationship with measures of personality, social interaction, psychological traits, and ability traits (77 biopsychosocial & ability [biopsy&ab] outcomes). Pain magnitude (out-of-sample [OOS] ) is associated with emotional control, attention, and working memory, with higher pain scores showing lower capacity to regulate and adapt behaviorally. Pain affect & disability (OOS associated with anxiety, catastrophizing and social relationships dysfunction. Pain quality did not relate significantly to biopsy&ab variables. Third, we mapped these 3 pain domains to brain functional connectivity. Pain magnitude mainly associated with the sensorimotor and the cingulo-opercular networks (OOS ). Pain affect & disability related to frontoparietal and default mode networks (OOS . Pain quality integrated sensorimotor, auditory, and cingulo-opercular networks (OOS ). Mediation analysis could link functional connectivity and biopsy&ab models to respective pain domains. Our results provide a global overview of the complexity of chronic pain, showing how underlying distinct domains of the experience map to different biopsy&ab correlates and underlie unique brain network signatures.

Raising Awareness on the Clinical and Social Relevance of Adequate Chronic Pain Care

Appropriate pain care should be regarded as a right and effectively guaranteed to people with chronic pain (CP). Law 38, enacted in Italy in 2010, establishes the citizen's right not to suffer. Twelve years later, such right appears still disregarded in Italy and the current access to adequate pain care reveals significant shortcomings. In addition, a mismatch between CP-associated burden and the available healthcare resources in the framework of our national health system has been observed. This article gathers the perspectives of a Board of Italian anesthesiologists on the state of the art of CP management in Italy and aims at strengthening the scientific rationale and clinical relevance of pursuing the enforceability of the right not to suffer and at promoting widespread multidisciplinary care of patients with CP.

Oncogenic role of microRNA-19b-3p-mediated SOCS3 in glioma through activation of JAK-STAT pathway

The altered expression of microRNA (miRNA) has been implicated in glioma. Here, the current study aimed to clarify the oncogenic effects of miR-19b-3p on cellular processes of glioma and to elucidate the underlying mechanism associated with SOCS3 and the JAK-STAT signaling pathway. Differentially expressed genes related to glioma were initially identified via microarray analysis. Twenty-five glioma patients were selected for clinical data collection, while additional 12 patients with traumatic brain injuries were selected as controls. Cell senescence was assessed by β-galactosidase staining, proliferation by MTT assay and apoptosis by flow cytometry following gain- and/or loss-of-function of miR-19b-3p or SOCS3. Glioma xenograft mouse model was developed through subcutaneous injection to nude mice to provide evidence in vivo. The glioma patients exhibited overexpressed miR-19b-3p and poorly-expressed SOCS3. SOCS3 was identified as a target gene of miR-19b-3p through dual-luciferase reporter gene assay. miR-19b-3p repressed SOCS3 expression and activated the JAK-STAT signaling pathway. Furthermore, miR-19b-3p inhibition promoted apoptosis and senescence, and suppressed cell proliferation through inactivation of the JAK-STAT signaling pathway and up-regulation of SOCS3. The reported regulatory axis was validated in nude mice as evidenced by suppressed tumor growth. Taken together, this study demonstrates that miR-19b-3p facilitates glioma progression via activation of the JAK-STAT signaling pathway by targeting SOCS3, highlighting a novel therapeutic target for glioma treatment.

The Impact of P-Glycoprotein on Opioid Analgesics: What's the Real Meaning in Pain Management and Palliative Care?

Opioids are widely used in cancer and non-cancer pain management. However, many transporters at the blood-brain barrier (BBB), such as P-glycoprotein (P-gp, ABCB1/MDR1), may impair their delivery to the brain, thus leading to opioid tolerance. Nonetheless, opioids may regulate P-gp expression, thus altering the transport of other compounds, namely chemotherapeutic agents, resulting in pharmacoresistance. Other kinds of painkillers (e.g., acetaminophen, dexamethasone) and adjuvant drugs used for neuropathic pain may act as P-gp substrates and modulate its expression, thus making pain management challenging. Inflammatory conditions are also believed to upregulate P-gp. The role of P-gp in drug-drug interactions is currently under investigation, since many P-gp substrates may also act as substrates for the cytochrome P450 enzymes, which metabolize a wide range of xenobiotics and endobiotics. Genetic variability of the ABCB1/MDR1 gene may be accountable for inter-individual variation in opioid-induced analgesia. P-gp also plays a role in the management of opioid-induced adverse effects, such as constipation. Peripherally acting mu-opioid receptors antagonists (PAMORAs), such as naloxegol and naldemedine, are substrates of P-gp, which prevent their penetration in the central nervous system. In our review, we explore the interactions between P-gp and opioidergic drugs, with their implications in clinical practice.

Systematic review of guideline-recommended medications prescribed for treatment of low back pain

OBJECTIVE

To identify and descriptively compare medication recommendations among low back pain (LBP) clinical practice guidelines (CPG).

METHODS

We searched PubMed, Cochrane Database of Systematic Review, Index to Chiropractic Literature, AMED, CINAHL, and PEDro to identify CPGs that described the management of mechanical LBP in the prior five years. Two investigators independently screened titles and abstracts and potentially relevant full text were considered for eligibility. Four investigators independently applied the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument for critical appraisal. Data were extracted for pharmaceutical intervention, the strength of recommendation, and appropriateness for the duration of LBP.

RESULTS

316 citations were identified, 50 full-text articles were assessed, and nine guidelines with global representation met the eligibility criteria. These CPGs addressed pharmacological treatments with or without non-pharmacological treatments. All CPGS focused on the management of acute, chronic, or unspecified duration of LBP. The mean overall AGREE II score was 89.3% (SD 3.5%). The lowest domain mean score was for applicability, 80.4% (SD 5.2%), and the highest was Scope and Purpose, 94.0% (SD 2.4%). There were ten classifications of medications described in the included CPGs: acetaminophen, antibiotics, anticonvulsants, antidepressants, benzodiazepines, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, oral corticosteroids, skeletal muscle relaxants (SMRs), and atypical opioids.

CONCLUSIONS

Nine CPGs, included ten medication classes for the management of LBP. NSAIDs were the most frequently recommended medication for the treatment of both acute and chronic LBP as a first line pharmacological therapy. Acetaminophen and SMRs were inconsistently recommended for acute LBP. Meanwhile, with less consensus among CPGs, acetaminophen and antidepressants were proposed as second-choice therapies for chronic LBP. There was significant heterogeneity of recommendations within many medication classes, although oral corticosteroids, benzodiazepines, anticonvulsants, and antibiotics were not recommended by any CPGs for acute or chronic LBP.

Analyzing the Impact of Cannabinoids on the Treatment of Spinal Disorders

PURPOSE OF REVIEW

Cannabis is among the most used illicit substances globally, with medical applications, increased legalization, and shifting social attitudes leading to increased use in recent years. Cannabinoids are a group of psychoactive substances found within the cannabis plant, with the most common being Δ9-tetrahydrocannabinol and cannabidiol. Due to the high prevalence of use, it is increasingly important to evaluate the effects of cannabis and cannabinoids on spine patients, in both operative and nonoperative settings.

RECENT FINDINGS

Cannabis and cannabinoids may be effective in treating patients with chronic conditions such as back pain and spinal cord injuries. Longitudinal effects and implications on surgical outcomes and complications are poorly understood. High-quality, outcomes-focused research can inform approaches for clinicians to approach cannabis and cannabinoid use. Studies to elucidate the standardization of cannabis regimens can help develop guidelines for potential therapeutic applications. Cannabis and cannabinoids may be useful alternatives or additions for many spine patients, but future research is needed for recommendations to be determined. Our manuscript reviews the available literature regarding cannabis use and various spinal conditions, organizing our findings into the following narrative themes: (1) the management of chronic lower back pain, (2) perioperative outcomes, (3) cannabis use in general orthopaedic procedures, and (4) spinal cord injuries.

Votucalis, a Novel Centrally Sparing Histamine-Binding Protein, Attenuates Histaminergic Itch and Neuropathic Pain in Mice

Votucalis is a biologically active protein in tick (R. appendiculatus) saliva, which specifically binds histamine with high affinity and, therefore, has the potential to inhibit the host's immunological responses at the feeding site. We hypothesized that scavenging of peripherally released endogenous histamine by Votucalis results in both anti-itch and anti-nociceptive effects. To test this hypothesis, adult male mice were subjected to histaminergic itch, as well as peripheral nerve injury that resulted in neuropathic pain. Thus, we selected models where peripherally released histamine was shown to be a key regulator. In these models, the animals received systemic (intraperitoneal, i.p.) or peripheral transdermal (subcutaneous, s.c. or intraplantar, i.pl.) administrations of Votucalis and itch behavior, as well as mechanical and thermal hypersensitivity, were evaluated. Selective histamine receptor antagonists were used to determine the involvement of histamine receptors in the effects produced by Votucalis. We also used the spontaneous object recognition test to confirm the centrally sparing properties of Votucalis. Our main finding shows that in histamine-dependent itch and neuropathic pain models peripheral (s.c. or i.pl.) administration of Votucalis displayed a longer duration of action for a lower dose range, when compared with Votucalis systemic (i.p.) effects. Stronger anti-itch effect was observed after co-administration of Votucalis (s.c.) and antagonists that inhibited peripheral histamine H1 and H2 receptors as well as central histamine H4 receptors indicating the importance of these histamine receptors in itch. In neuropathic mice, Votucalis produced a potent and complete anti-nociceptive effect on mechanical hypersensitivity, while thermal (heat) hypersensitivity was largely unaffected. Overall, our findings further emphasize the key role for histamine in the regulation of histaminergic itch and chronic neuropathic pain. Given the effectiveness of Votucalis after peripheral transdermal administration, with a lack of central effects, we provide here the first evidence that scavenging of peripherally released histamine by Votucalis may represent a novel therapeutically effective and safe long-term strategy for the management of these refractory health conditions.

A diagnostic tool for people with lumbar instability: a criterion-related validity study

BACKGROUND

Several clinical tests used to identify patients with lumbar instability have reported diagnostic accuracy in separate studies with conflicting results. To augment the diagnostic process, tests that are better able to identify lumbar instability suitable for use in the clinical setting are required. The aim of this study was to identify the probability to diagnose patients with lumbar instability, using x-ray imaging as the reference standard.

METHODS

This study was a cross-sectional, diagnostic validity study. One hundred forty participants with chronic low back pain underwent an x-ray assessment and 14 clinical examinations. Data were analysed using multivariate regression methods to determine which clinical tests were most diagnostic for lumbar instability when they were applied together.

RESULTS

Eighteen (12.85%) participants had radiological lumbar instability. Three clinical tests i) interspinous gap change during flexion-extension, ii) passive accessory intervertebral movement tests, iii) posterior shear test demonstrated an ability to diagnose lumbar instability of 67% when they were all positive. At this probability threshold, sensitivity, specificity, positive likelihood ratio (+LR), and negative likelihood ratio (-LR) were 5.56, 99.18%, 6.78, and 0.95.

CONCLUSIONS

These 3 clinical tests could be useful in identifying patients with lumbar instability in the general community. These three tests are simple to perform by physical therapists, reliable to use in a clinical setting, and safe for patients. We recommend physical therapists use these three tests to assess patients who are suspected of having lumbar instability, in the absence of an x-ray assessment, to receive appropriate targeted intervention or referral for further investigation.

TRIAL REGISTRATION

Thai Clinial Trial Registry (TCTR 20180820001; 19th August 2018).

Effects of a Remotely Delivered Cognitive Behavioral Coaching Program on the Self-Rated Functional Disability of Participants with Low Back Pain

PURPOSE

A remotely delivered cognitive behavioral coaching (CBC) program was offered as a service benefit for commercial health plan members with low back pain (LBP). This study describes changes in self-rated functional disability in a sample of plan members participating in the program (N=423).

METHODS

Independent measures included demographics, length of program enrollment, total CBC sessions, and baseline self-reported patient activation and presenteeism levels. Participants rated their functional disability level due to LBP using the Oswestry Disability Index (ODI). Dependent outcomes quantified change in participant functional disability rating (final ODI score minus baseline ODI score). Nonparametric tests compare differences between groups and within-group ODI score change. Two generalized linear models test for associations between independent variables and the ODI change score.

RESULTS

A significant difference between baseline and final ODI scores was observed at the overall program level (p<.001) and within all independent variable categories of interest. Over 68% of total participants (n=289) reported improved functional ability from baseline to final (decrease in ODI score). Participants who completed more CBC sessions demonstrated significantly greater improvement in functional ability (p=.038) compared to those who completed fewer sessions. Participants aged 55 and older were significantly more likely to show deterioration in functional ability from baseline to final (p=.021).

CONCLUSION

Outcomes suggest that program participation can influence self-rated functional disability in the management of LBP.

The role of dorsal root ganglia alpha-7 nicotinic acetylcholine receptor in complete Freund's adjuvant-induced chronic inflammatory pain

BACKGROUND

Alpha-7 nicotinic acetylcholine receptor (α7 nAChR) was reported to have a critical role in the regulation of pain sensitivity and neuroinflammation. However, the expression level of α7 nAChR in dorsal root ganglion (DRG) and the underlying neuroinflammatory mechanisms associated with hyperalgesia are still unknown.

METHODS

In the present study, the expression and mechanism of α7 nAChR in chronic inflammatory pain was investigated using a complete Freund's adjuvant (CFA)-induced chronic inflammatory pain model. Subsequently, a series of assays including immunohistochemistry, western blotting, and quantitative real-time polymerase chain reaction (qRT-PCR) were performed.

RESULTS

α7 nAChR was mostly colocalized with NeuN in DRG and upregulated after CFA injection. Microinjection of α7 nAChR siRNA into ipsilateral L4/5 DRGs aggravated the CFA-induced pain hypersensitivity. Intrathecal α7 nAChR agonist GTS-21 attenuated the development of CFA-induced mechanical and temperature-related pain hypersensitivities. In neuronal the SH-SY5Y cell line, the knockdown of α7 nAChRs triggered the upregulation of TRAF6 and NF-κB under CFA-induced inflammatory conditions, while agitation of α7 nAChR suppressed the TRAF6/NF-κB activation. α7 nAChR siRNA also exacerbated the secretion of pro-inflammatory mediators from LPS-induced SH-SY5Y cells. Conversely, α7 nAChR-specific agonist GTS-21 diminished the release of interleukin-1beta (IL-1β), IL-6, IL-8, and tumor necrosis factor-α (TNFα) in SH-SY5Y cells under inflammatory conditions. Mechanistically, the modulation of pain sensitivity and neuroinflammatory action of α7 nAChR may be mediated by the TRAF6/NF-κB signaling pathway.

CONCLUSIONS

The findings of this study suggest that α7 nAChR may be potentially utilized as a therapeutic target for therapeutics of chronic inflammatory pain.

Acute effects of proprioceptive neuromuscular facilitation exercises on the postural strategy in patients with chronic low back pain

INTRODUCTION

Active treatments focused on improvement in motor function are postulated in chronic low back patients (CLBP).

OBJECTIVE

to establish the acute effects of PNF exercise on the postural control strategy.

METHODS

The sway of the body was tested before intervention in fifty-three CLBP patients and after that participants were randomly assigned into the intervention PNF group (n = 25). Mean velocity (VEL) and sample entropy (SEn), over the center of pressure in the mediolateral (ML) and anterior-posterior (AP) planes served to estimate the postural strategy and automaticity levels in the neuromuscular controller. Tandem and one-leg standing tests (OLST) with eyes open and eyes closed were used.

RESULTS

Pain intensity decreased after the intervention. The VEL was no longer vision-dependent in both planes. The SEn decreased immediately after the exercise and either returned to or even exceeded the baseline values in the OLST ML plane.

CONCLUSION

A single session of PNF exercise may have a beneficial effect on pain and postural control in CLBP patients. The statistically significant pain relief combined with newly acquired better control of posture may have encouraged the PNF group participants to a subconscious exploration of the stability area. Postural movements were more automatized in OLST in the delayed test.

Peripheral and Central Pathological Mechanisms of Chronic Low Back Pain: A Narrative Review

Chronic low back pain (CLBP), lasting >3 months, is the end result of multiple pathogenic factors. Unfortunately, little is known about CLBP pathogenesis, which limits its advancements in clinical therapy and disease management. This paper summarizes the known pathological axes of CLBP, involving both peripheral and central systems. In particular, this paper details injurious nerve stimulation, inflammation-induced peripheral pathway, and central sensitization. Lumbar components, such as intervertebral disc (IVD), facet joints, muscles, fascia, ligaments, and joint capsules, contain pain receptors called nociceptors. Degeneration of the aforementioned lumbar components activates inflammatory pathways, which can directly damage nerves, lower nociceptor threshold to fire action potentials (AP), and cause pain. Additionally, damaged lumbar IVDs and endplates can also lead to the pathologic invasion of nerve growth and innervation, followed by the compression of herniated IVDs on nerve roots, thereby causing traumatic neuropathic pain. The central mechanism of CLBP involves alteration of the sensory processing of the brain and malfunction of the descending pain modulatory system, which facilitates pain amplification in the center nervous system (CNS). Lastly, abnormalities in the brain biochemical metabolism, activation of glial cells, and subsequent inflammation also play important roles in CLBP development. Taken together, inflammation plays an important role in both peripheral and central sensitization of CLBP. Due to the heterogeneity of CLBP, its pathological mechanism remains complex and difficult to understand. Therefore, it is a worthy field for future research into the subcomponents of CLBP pathogenesis, in order to distinguish the specific form of the disease, identify its origins, and develop corresponding highly effective comprehensive therapy against CLBP.

[CT-guided pain management of specific low back pain : Disc impairment vs. osseous degeneration]

Hintergrund

Rückenschmerz ist häufig und führt den Patienten sowohl zur Diagnostik als auch in bestimmten Fällen für eine Therapie zum Radiologen.

Fragestellung

Die vorliegende Untersuchung vergleicht die schmerzreduzierende Wirkung der mikroinvasiven Computertomographie(CT)-gesteuerten Schmerztherapie bei diskogenem und spondylarthrotisch bedingtem spezifischem Rückenschmerz.

Material und Methode

Über einen Zeitraum von 3,3 Jahren wurden 239 Patienten in die Untersuchung eingeschlossen, bei denen 686 CT-gesteuerte periradikuläre Therapien (PRT) und 264 CT-gesteuerte Facettengelenktherapien (FAC) durchgeführt und beurteilt wurden. Bei allen Patienten wurde vor der Intervention, im Verlauf und am Ende der Schmerzscore mittels visueller analoger Schmerzskala (VAS) bestimmt. Abschließend wurde der Behandlungserfolg in Abhängigkeit von der durchgeführten Behandlungsart und den morphologisch vorliegenden Veränderungen korreliert.

Ergebnisse

In beiden Gruppen zeigte sich unter der Behandlung eine gute Beschwerdebesserung (74 % bei PRT-Patienten und 60 % bei FAC-Patienten). Die Patienten, bei denen eine PRT durchgeführt wurde, zeigten durchschnittlich eine Verbesserung des Schmerzscores von 3,1, bei Patienten mit durchgeführter FAC von 2,1. Die Wirksamkeit der FAC zeigte eine Abhängigkeit der Wirksamkeit vom Grad der vorhandenen degenerativen Veränderungen. Je ausgeprägter die nachgewiesene Degeneration im behandelten Segment war, desto mehr Interventionen waren für ein gutes Therapieansprechen notwendig.

Schlussfolgerung

Die CT-gesteuerte PRT und FAC führen beide zu einer guten Reduktion der Beschwerdesymptomatik. Im Vergleich erzielte die PRT eine signifikant höhere Schmerzreduktion als die FAC.

Topical Treatments and Their Molecular/Cellular Mechanisms in Patients with Peripheral Neuropathic Pain-Narrative Review

Neuropathic pain in humans results from an injury or disease of the somatosensory nervous system at the peripheral or central level. Despite the considerable progress in pain management methods made to date, peripheral neuropathic pain significantly impacts patients' quality of life, as pharmacological and non-pharmacological methods often fail or induce side effects. Topical treatments are gaining popularity in the management of peripheral neuropathic pain, due to excellent safety profiles and preferences. Moreover, topical treatments applied locally may target the underlying mechanisms of peripheral sensitization and pain. Recent studies showed that peripheral sensitization results from interactions between neuronal and non-neuronal cells, with numerous signaling molecules and molecular/cellular targets involved. This narrative review discusses the molecular/cellular mechanisms of drugs available in topical formulations utilized in clinical practice and their effectiveness in clinical studies in patients with peripheral neuropathic pain. We searched PubMed for papers published from 1 January 1995 to 30 November 2020. The key search phrases for identifying potentially relevant articles were "topical AND pain", "topical AND neuropathic", "topical AND treatment", "topical AND mechanism", "peripheral neuropathic", and "mechanism". The result of our search was 23 randomized controlled trials (RCT), 9 open-label studies, 16 retrospective studies, 20 case (series) reports, 8 systematic reviews, 66 narrative reviews, and 140 experimental studies. The data from preclinical studies revealed that active compounds of topical treatments exert multiple mechanisms of action, directly or indirectly modulating ion channels, receptors, proteins, and enzymes expressed by neuronal and non-neuronal cells, and thus contributing to antinociception. However, which mechanisms and the extent to which the mechanisms contribute to pain relief observed in humans remain unclear. The evidence from RCTs and reviews supports 5% lidocaine patches, 8% capsaicin patches, and botulinum toxin A injections as effective treatments in patients with peripheral neuropathic pain. In turn, single RCTs support evidence of doxepin, funapide, diclofenac, baclofen, clonidine, loperamide, and cannabidiol in neuropathic pain states. Topical administration of phenytoin, ambroxol, and prazosin is supported by observational clinical studies. For topical amitriptyline, menthol, and gabapentin, evidence comes from case reports and case series. For topical ketamine and baclofen, data supporting their effectiveness are provided by both single RCTs and case series. The discussed data from clinical studies and observations support the usefulness of topical treatments in neuropathic pain management. This review may help clinicians in making decisions regarding whether and which topical treatment may be a beneficial option, particularly in frail patients not tolerating systemic pharmacotherapy.

Peripheral Mechanisms of Neuropathic Pain-the Role of Neuronal and Non-Neuronal Interactions and Their Implications for Topical Treatment of Neuropathic Pain

Neuropathic pain in humans arises as a consequence of injury or disease of somatosensory nervous system at peripheral or central level. Peripheral neuropathic pain is more common than central neuropathic pain, and is supposed to result from peripheral mechanisms, following nerve injury. The animal models of neuropathic pain show extensive functional and structural changes occurring in neuronal and non-neuronal cells in response to peripheral nerve injury. These pathological changes following damage lead to peripheral sensitization development, and subsequently to central sensitization initiation with spinal and supraspinal mechanism involved. The aim of this narrative review paper is to discuss the mechanisms engaged in peripheral neuropathic pain generation and maintenance, with special focus on the role of glial, immune, and epithelial cells in peripheral nociception. Based on the preclinical and clinical studies, interactions between neuronal and non-neuronal cells have been described, pointing out at the molecular/cellular underlying mechanisms of neuropathic pain, which might be potentially targeted by topical treatments in clinical practice. The modulation of the complex neuro-immuno-cutaneous interactions in the periphery represents a strategy for the development of new topical analgesics and their utilization in clinical settings.

Differences in physical and psychological health in patients with chronic low back pain: a national survey in general Spanish population

PURPOSE

To estimate the prevalence of diagnosed and undiagnosed chronic low back pain (CLBP-D and CLBP-UD, respectively) in the general adult population in Spain and to compare the characteristics of these two groups with subjects without CLBP symptoms (No-CLBP). To establish CLBP-D patient sub-groups according to their self-perceived health status, mental health, level of pain and the impact of their pain on daily activities.

METHODS

Data were obtained from the National Health Survey of Spain 2017 with a sample of 23,089 adults. Three groups were defined: CLBP-D, CLBP-UD and No-CLBP. In the CLBP-D group, a cluster analysis was performed to identify sub-groups. A multinomial regression model was constructed to determine the factors associated with each of the sub-groups identified.

RESULTS

The prevalence of CLBP-D was 22% (95% CI 21.5-22.5) and that of CLBP-UD was 1.4% (95% CI 1.2-1.5). CLBP-D was more common in middle-aged females with a low educational level. They have a worse perceived health status, report more comorbidities, have worse mental health and more limitations in comparison with the populations without CLBP and with CLBP-UD. Three sub-groups of CLBP-D subjects were identified. Women and older subjects with a lower educational level, more occupational stress, less social support and with more physical limitations were the most likely subjects to be included in the group worst-affected.

CONCLUSIONS

There is a high prevalence of CLBP among the adult population in Spain. Occupational stress and a lack of social support are common factors among subjects' worst-affected of CLBP-D and identifying the subjects with these risks is therefore a recommended strategy for improving the healthcare provided to CLBP patients.

Evaluating Cortical Alterations in Patients With Chronic Back Pain Using Neuroimaging Techniques: Recent Advances and Perspectives

Chronic back pain (CBP) is a leading cause of disability and results in considerable socio-economic burdens worldwide. Although CBP patients are commonly diagnosed and treated with a focus on the “end organ dysfunction” (i.e., peripheral nerve injuries or diseases), the evaluation of CBP remains flawed and problematic with great challenges. Given that the peripheral nerve injuries or diseases are insufficient to define the etiology of CBP in some cases, the evaluation of alterations in the central nervous system becomes particularly necessary and important. With the development of advanced neuroimaging techniques, extensive studies have been carried out to identify the cortical abnormalities in CBP patients. Here, we provide a comprehensive overview on a series of novel findings from these neuroimaging studies to improve our understanding of the cortical abnormalities originated in the disease. First, CBP patients normally exhibit central sensitization to external painful stimuli, which is indexed by increased pain sensitivity and brain activations in pain-related brain regions. Second, long-term suffering from chronic pain leads to emotional disorders, cognitive impairments, and the abnormalities of the relevant brain networks among CBP patients. Third, CBP is associated with massive cortical reorganization, including structural, functional, and metabolic brain changes. Overall, a deep insight into the neural mechanisms underlying the development and outcome of CBP through more sophisticated neuroimaging investigations could not only improve our current understanding of the etiology of CBP but also facilitate the diagnosis and treatment of CBP based on precision medicine.

Adjuvant analgesics in spinal surgery

Peri- and postoperative pain control can present a challenge to any doctor, particularly in the setting of spinal surgery. The use of adjuvant pain agents and multimodal analgesia is changing the face of modern anaesthesia and offering clinicians more avenues to control perioperative pain. This article discusses the use of adjuvant medications and some of the evidence surrounding their use in spinal surgery.

Current understanding of the mixed pain concept: a brief narrative review

Despite having been referenced in the literature for over a decade, the term "mixed pain" has never been formally defined. The strict binary classification of pain as being either purely neuropathic or nociceptive once left a good proportion of patients unclassified; even the recent adoption of "nociplastic pain" in the IASP Terminology leaves out patients who present clinically with a substantial overlap of nociceptive and neuropathic symptoms. For these patients, the term "mixed pain" is increasingly recognized and accepted by clinicians. Thus, an independent group of international multidisciplinary clinicians convened a series of informal discussions to consolidate knowledge and articulate all that is known (or, more accurately, thought to be known) and all that is not known about mixed pain. To inform the group's discussions, a Medline search for the Medical Subject Heading "mixed pain" was performed via PubMed. The search strategy encompassed clinical trial articles and reviews from January 1990 to the present. Clinically relevant articles were selected and reviewed. This paper summarizes the group's consensus on several key aspects of the mixed pain concept, to serve as a foundation for future attempts at generating a mechanistic and/or clinical definition of mixed pain. A definition would have important implications for the development of recommendations or guidelines for diagnosis and treatment of mixed pain.

Responsiveness of Minimal Clinically Important Change for the Persian Functional Rating Index in Patients with Chronic Low Back Pain

STUDY DESIGN

A prospective, within-group cohort study of 46 patients with chronic low-back pain (CLBP).

PURPOSE

To assess the responsiveness of the Persian Functional Rating Index (PFRI) and to determine the minimal clinically important change (MCIC) of the PFRI in a cohort of patients with CLBP.

OVERVIEW OF LITERATURE

The FRI is an instrument for assessing pain and disability in patients with low-back pain. No study so far has examined the responsiveness of the PFRI.

METHODS

Forty-six patients with CLBP with a mean age of 50.33±14.28 completed the PFRI, the Persian Roland-Morris Disability Questionnaire (PRMDQ), and a Visual Analog Scale (VAS) before and after 10 physiotherapy sessions. A Global Rating of Change Scale (GRCS) was completed after treatment.

RESULTS

The changes in PFRI scores were statistically significant using the paired t-test (p<0.001). The PFRI revealed high effect sizes (range, 0.93-1.82). The PFRI showed significant correlations with the VAS (0.86), the PRMDQ (0.66), and the GRCS (0.45). The area under the receiver operator characteristic curve for the PFRI was good (0.76; 95% confidence interval, 0.56-0.95). The MCIC for PFRI was 10.63 points.

CONCLUSIONS

The results supported the responsiveness of the PFRI in patients with CLBP and showed the amount of change in PFRI scores perceived as worthwhile by the patients.

Assessing and Treating Chronic Pain in Patients with End-Stage Renal Disease

Pain is one of the most common symptoms among patients with end-stage renal disease (ESRD), and is often under recognized and not adequately managed in hemodialysis (HD) patients. Barriers to adequate pain management include poor awareness of the problem, insufficient medical education, fears of possible drug-related side effects, and common misconceptions about the inevitability of pain in elderly and HD patients. Caregivers working in HD should be aware of the possible consequences of inadequate pain assessment and management. Common pain syndromes in HD patients include musculoskeletal diseases and metabolic neuropathies, associated with typical intradialytic pain. Evaluating the etiology, nature, and intensity of pain is crucial for choosing the correct analgesic. A mechanism-based approach to pain management may result in a better outcome. Pharmacokinetic considerations on clearance alterations and possible toxicity in patients with ESRD should drive the right analgesic prescription. Comorbidities and polymedications may increase the risk of drug-drug interactions, therefore drug metabolism should be taken into account when selecting analgesic drugs. Automedication is common among HD patients but should be avoided to reduce the risk of hazardous drug administration. Further research is warranted to define the efficacy and safety of analgesic drugs and techniques in the context of patients with ESRD as generalizing information from studies conducted in the general population could be inappropriate and potentially dangerous. A multidisciplinary approach is recommended for the management of complex pain syndromes in frail patients, such as those suffering from ESRD.

Pain chronification: what should a non-pain medicine specialist know?

OBJECTIVE

Pain is one of the most common reasons for an individual to consult their primary care physician, with most chronic pain being treated in the primary care setting. However, many primary care physicians/non-pain medicine specialists lack enough awareness, education and skills to manage pain patients appropriately, and there is currently no clear, common consensus/formal definition of "pain chronification".

METHODS

This article, based on an international Change Pain Chronic Advisory Board meeting which was held in Wiesbaden, Germany, in October 2016, provides primary care physicians/non-pain medicine specialists with a narrative overview of pain chronification, including underlying physiological and psychosocial processes, predictive factors for pain chronification, a brief summary of preventive strategies, and the role of primary care physicians and non-pain medicine specialists in the holistic management of pain chronification.

RESULTS

Based on currently available evidence, we propose the following consensus-based definition of pain chronification which provides a common framework to raise awareness among non-pain medicine specialists: "Pain chronification describes the process of transient pain progressing into persistent pain; pain processing changes as a result of an imbalance between pain amplification and pain inhibition; genetic, environmental and biopsychosocial factors determine the risk, the degree, and time-course of chronification."

CONCLUSIONS

Early intervention plays an important role in preventing pain chronification and, as key influencers in the management of patients with acute pain, it is critical that primary care physicians are equipped with the necessary awareness, education and skills to manage pain patients appropriately.

Magnetic Resonance Neurography in Chronic Lumbosacral and Pelvic Pain: Diagnostic and Management Impact-Institutional Audit

BACKGROUND/OBJECTIVE

Low back and pelvic pain are among the most prevalent conditions worldwide, with major social and economic costs. The aim of this study was to evaluate the role of magnetic resonance neurography (MRN) of lumbosacral plexus in the management and outcomes of these patients with chronic pain.

METHODS

Consecutive patients with chronic lumbosacral and pelvic pain referred for MRN over a year were included. Preimaging and postimaging clinical diagnosis and treatment, pain levels, and location were recorded. Pain-free survival was compared between treatments using a Cox proportional hazards model.

RESULTS

A total of 202 patients with mean age 53.7 ± 14.8 years and a male/female ratio of 1:1.53 were included. Of these patients, 115 presented with radiculopathy (57%), 56 with pelvic pain (28%), and 31 with groin pain (15%). Mean initial pain level was 6.9 ± 1.9. Mean symptom duration was 4.21 ± 5.86 years. Of these patients, 143 (71%) had a change in management because of MRN. After MRN, reduction in pain levels was observed in 21 of 32 patients receiving conservative treatment (66%), 42 of 67 receiving injections (63%), and 27 of 33 receiving surgery (82%). Follow-ups were available in 131 patients. Median pain-free survival was 12 months. Patients treated with surgery had significantly lower pain recurrence than patients receiving other treatments in the same time frame (hazard ratio, 3.6; 95% confidence interval, 1.4-9.2; P = 0.0061).

CONCLUSIONS

MRN use in chronic lumbosacral and pelvic pain led to a meaningful change in diagnosis and treatment. After MRN, conservative treatment and injections provided pain relief; however, patients benefited more from surgery than from any other treatment.

Does a Better Perfusion of Deconditioned Muscle Tissue Release Chronic Low Back Pain?

Non-specific chronic low back pain (nsCLBP) is a multifactorial condition of unknown etiology and pathogenesis. Physical and genetic factors may influence the predisposition of individuals to CLBP, which in many instances share a musculoskeletal origin. A reduced pain level in low back pain patients that participate in exercise therapy highlights that disuse-related muscle deconditioning may predispose individuals to nsCLBP. In this context, musculoskeletal pain may be the consequence of capillary rarefaction in inactive muscle as this would lower local tissue drainage and washing out of toxic waste. Muscle activity is translated into an angio-adaptative process, which implicates angiogenic-gene expression and individual response differences due to heritable modifications of such genes (gene polymorphisms). The pathophysiologic mechanism underlying nsCLBP is still largely unaddressed. We hypothesize that capillary rarefaction due to a deconditioning of dorsal muscle groups exacerbates nsCLBP by increasing noxious sensation, reducing muscle strength and fatigue resistance by initiating a downward spiral of local deconditioning of back muscles which diminishes their load-bearing capacity. We address the idea that specific factors such as angiotensin-converting enzyme and Tenascin-C might play an important role in altering susceptibility to nsCLBP via their effects on microvascular perfusion and vascular remodeling of skeletal muscle, inflammation, and pain sensation. The genetic profile may help to explain the individual predisposition to nsCLBP, thus identifying subgroups of patients, which could benefit from ad hoc treatment types. Future therapeutic approaches aimed at relieving the pain associated with nsCLBP should be based on the verification of mechanistic processes of activity-induced angio-adaptation and muscle-perfusion.