Caring for patients with chronic pain: pearls and pitfalls

Neuroimmune Pain and Its Manipulation by Pathogens

Recent studies highlight extensive crosstalk that exists between sensory neurons responsible for pain and the immune system. Cutaneous pain neurons detect harmful microbes, recruit immune cells, and produce anticipatory immunity in nearby tissues. These complementary systems generally protect hosts from infections. At the same time, neuroimmune pain is vulnerable to manipulation. Some pathogens evade immunity activated by nociceptors by producing opioid analogs and by interfering with sensory nerve function. Other organisms manipulate neuroimmune pain by increasing it. Hosts may gain protection from interference by adjusting pain sensitivity. Nociceptive sensitization follows expectations of signal detection theory and the smoke detector principle, allowing pain to be more easily triggered in response to microbial threats and damage. However, pain sensitization at the spinal level and cortical responses to pain are themselves the target of manipulation by parasites and other organisms. Here we review examples of parasites, bacteria, and other medically important organisms that interfere with pain signaling and describe their implications for public health, infectious disease, and the treatment of pain.

Prevention of Opioid Misuse and Abuse Through Effective Pain Management in Patients With Chronic Pain: An Umbrella Systematic Review

Chronic pain is a condition that frequently affects patients and communities. There are several treatment options available, including both pharmacological and non-pharmacological. Opioid prescriptions have increased over the past few years, and long-term use of opioids leads to an increased risk of opioid misuse and death due to overdose. This systematic review discusses the effective pain management options in chronic non-cancer pain patients that may help prevent opioid use and misuse. We searched PubMed, PubMed Central (PMC), Medical Literature Analysis and Retrieval System Online (MEDLINE), Multidisciplinary Digital Publishing Institute (MDPI), and Google Scholar for relevant literature. The different results were screened by the application of eligibility criteria, and 15 papers were finalized for review. These papers discussed the different pain management options, physician guidelines, and efforts to reduce opioid misuse, the importance of pill counting, and the involvement of multidisciplinary care teams in pain management. However, most of these papers were reviews over a short duration. The effects of emotions on chronic pain have been discussed along with the multidisciplinary pain rehabilitation treatment options that have improved patients' overall function. The reviewed research demonstrated positive outcomes of spinal cord stimulation in chronic low back pain, thereby reducing opioid use. However, further research is needed to explore more treatment options for chronic pain that can adequately reduce pain and prevent opioid use.

Exploring Factors Associated with Prescribers' Comfort Levels in Analgesic Prescribing in Quebec

Purpose

Identifying the factors associated with comfort level when prescribing medications is important for tailoring education and training. This study aimed to explore factors associated with the comfort level of healthcare professionals regarding dispensing and adjusting prescriptions for the treatment of chronic pain (CP).

Methods

A cross-sectional survey was conducted among licensed physicians, pharmacists, and nurse practitioners across the province of Quebec, Canada. Comfort level regarding dispensing and/or adjusting prescriptions for CP treatment was measured on a 0-10 rating scale (0 = very uncomfortable, 10 = very comfortable).

Results

In total, 207 prescribers participated in this study (83 physicians, 58 pharmacists, and 66 nurse practitioners). 56.5% reported a comfort level in dispensing and/or adjusting prescriptions for the treatment of CP <6/10. The median comfort level score was 6 (interquartile range - IQR: 2). Differences in median scores were found between physicians (6), pharmacists (7) and nurses (5; p < 0.001). Multivariable logistic regression revealed that the factors associated with an increased likelihood of reporting a high comfort level (≥6/10) were: being a pharmacist, having a relative living with CP, a greater percentage of past year continuing educational activities about CP management, and higher perception of short-acting opioids risks. Factors associated with lower comfort levels were as follows: being a nurse practitioner, having fewer years of experience, living in a remote region, living with CP, and a higher perception of long-acting opioids risks. The practice setting and sex at birth were also associated with comfort level.

Conclusion

The comfort level regarding prescribing for CP varies according to socioeconomic/professional factors, which can lead to disparities in the quality of care and outcomes for patients. Our results reinforce the importance of investing in initial training and continuing education of prescribers.

Efficacy and Safety of High Density LED Irradiation Therapy for Patients With Hand Osteoarthritis: A Single-Center Clinical Study

OBJECTIVE

To assess the safety and effectiveness of high-density light-emitting diode (LED) irradiation therapy in patients with hand osteoarthritis (OA) and compare the pre- and post-intervention symptoms.

METHODS

Twenty-three patients with hand OA underwent eight sessions of high-density LED irradiation therapy directed at the five most painful areas in the finger joints. Each session lasted for 18 minutes; and the sessions were conducted twice a week, for 4 weeks. We evaluated the degree of pain using the visual analogue scale, ring size, and passive range of motion (flexion+extension) for two most painful joints from the baseline to post-therapy (weeks 4 and 6).

RESULTS

High-density LED irradiation therapy significantly reduced the pain posttreatment compared with that observed at the baseline (p<0.001). Although improvements were observed in ring size and joint range of motion at 4 and 6 weeks, they were not statistically significant (p>0.05). No adverse events were observed.

CONCLUSION

We examined the safety and effectiveness of high-density LED irradiation therapy in reducing pain and hand swelling and improving joint mobility in patients with hand OA. These results suggest that high-density LED irradiation therapy has the potential to be an important strategy for managing hand OA.

The NLRP3 inflammasome: role in the pathobiology of chronic pain

Chronic pain is not only one of the most common health problems, it is often challenging to treat adequately. Chronic pain has a high prevalence globally, affecting approximately 20% of the adult population. Chronic inflammatory pain and neuropathic (nerve) pain conditions are areas of large unmet medical need because analgesic/adjuvant agents recommended for alleviation of these types of chronic pain often lack efficacy and/or they produce dose-limiting side effects. Recent work has implicated the NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome in the pathobiology of chronic pain, especially neuropathic and inflammatory pain conditions. NLRP3 is activated by damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs). This in turn leads to recruitment and activation of caspase-1 an enzyme that cleaves the inactive IL-1β and IL-18 precursors to their respective mature pro-inflammatory cytokines (IL-1β and IL-18) for release into the cellular milieu. Caspase-1 also cleaves the pyroptosis-inducing factor, gasdermin D, that leads to oligomerization of its N-terminal fragment to form pores in the host cell membrane. This then results in cellular swelling, lysis and release of cytoplasmic contents in an inflammatory form of cell death, termed pyroptosis. The ultimate outcome may lead to the development of neuropathic pain and/or chronic inflammatory pain. In this review, we address a role for NLRP3 inflammasome activation in the pathogenesis of various chronic pain conditions.

Microglia polarization in nociplastic pain: mechanisms and perspectives

Nociplastic pain is the third classification of pain as described by the International Association for the Study of Pain (IASP), in addition to the neuropathic and nociceptive pain classes. The main pathophysiological mechanism for developing nociplastic pain is central sensitization (CS) in which pain amplification and hypersensitivity occur. Fibromyalgia is the prototypical nociplastic pain disorder, characterized by allodynia and hyperalgesia. Much scientific data suggest that classical activation of microglia in the spinal cord mediates neuroinflammation which plays an essential role in developing CS. In this review article, we discuss the impact of microglia activation and M1/M2 polarization on developing neuroinflammation and nociplastic pain, besides the molecular mechanisms engaged in this process. In addition, we mention the impact of microglial modulators on M1/M2 microglial polarization that offers a novel therapeutic alternative for the management of nociplastic pain disorders. Illustrating the mechanisms underlying microglia activation in central sensitization and nociplastic pain. LPS lipopolysaccharide, TNF-α tumor necrosis factor-α, INF-γ Interferon gamma, ATP adenosine triphosphate, 49 P2Y12/13R purinergic P2Y 12/13 receptor, P2X4/7R purinergic P2X 4/7 receptor, SP Substance P, NK-1R Neurokinin 1 receptor, CCL2 CC motif ligand 2, CCR2 CC motif ligand 2 receptor, CSF-1 colony-stimulating factor 1, CSF-1R colony-stimulating factor 1 receptor, CX3CL1 CX3C motif ligand 1, CX3XR1 CX3C motif ligand 1 receptor, TLR toll-like receptor, MAPK mitogen-activated protein kinases, JNK jun N-terminal kinase, ERK extracellular signal-regulated kinase, iNOS Inducible nitric oxide synthase, IL-1β interleukin-1β, IL-6 interleukin-6, BDNF brain-derived neurotrophic factor, GABA γ-Aminobutyric acid, GABAR γ-Aminobutyric acid receptor, NMDAR N-methyl-D-aspartate receptor, AMPAR α-amino-3-hydroxy-5-methyl-4-isoxazolepropi-onic acid receptor, IL-4 interleukin-4, IL-13 interleukin-13, IL-10 interleukin-10, Arg-1 Arginase 1, FGF fibroblast growth factor, GDNF glial cell-derived neurotrophic factor, IGF-1 insulin-like growth factor-1, NGF nerve growth factor, CD Cluster of differentiation.

Evaluation of Analgesic and Anti-inflammatory Activities of Methanolic Leaf and Root Extracts of Gomphocarpus purpurascens A. Rich (Asclepiadaceae) in Mice

Background

Regardless of the availability of drugs many people still experienced pain and inflammation because current medications often trigger potentially serious adverse effects. A range of medicinal plants with analgesic and anti-inflammatory properties have been widely used by traditional healers. Among them, Gomphocarpus purpurascens is one however there are no experimental studies that support this traditional use.

Objective

This study aimed to evaluate the analgesic and anti-inflammatory activities of 80% methanolic leaf and root extracts of G. purpurascens.

Methods

Air-dried leaves and roots of G. purpurascens were extracted with 80% methanol and an acute oral toxicity study was conducted for the 80% methanolic extract of G. purpurascens according to OECD guideline version eighteen. Preliminary phytochemical screening for the presence of different constituents was carried out. The hot plate method was used to evaluate centrally mediated analgesic activity while peripheral analgesic activity was tested by an acetic acid-induced writhing test. Carrageenan-induced paw edema test and formalin-induced pedal edema test were used to evaluate anti-inflammatory activity.

Results

Dose-dependent inhibition of acetic acid-induced writhing test was observed in mice by 100 mg/kg, 200 mg/kg, and 400 mg/kg of root extract with respective values of 16.6%, 68.9%, and 83%. In the hot plate method, the root extract at doses of 200mg/kg and 400 mg/kg showed a significant (p < 0.05) analgesic effect. Maximum anti-inflammatory effects by all doses of leaf extracts were observed from 2-4hr post-induction in carrageenan-induced paw edema; and all tested doses of the extract inhibited the formalin-induced inflammation significantly (p < 0.001, p < 0.01). The presence of saponins, alkaloids, flavonoids, tannins, terpenoids, anthraquinone, steroids, and phenols might be responsible for these activities.

Conclusion

This study shows that the extract had potential analgesic and anti-inflammatory activity which supports the traditional claim.

Artificial Neural Networks Coupled with MALDI-TOF MS Serum Fingerprinting To Classify and Diagnose Pathological Pain Subtypes in Preclinical Models

Pathological pain subtypes can be classified as either neuropathic pain, caused by a somatosensory nervous system lesion or disease, or nociplastic pain, which develops without evidence of somatosensory system damage. Since there is no gold standard for the diagnosis of pathological pain subtypes, the proper classification of individual patients is currently an unmet challenge for clinicians. While the determination of specific biomarkers for each condition by current biochemical techniques is a complex task, the use of multimolecular techniques, such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), combined with artificial intelligence allows specific fingerprints for pathological pain-subtypes to be obtained, which may be useful for diagnosis. We analyzed whether the information provided by the mass spectra of serum samples of four experimental models of neuropathic and nociplastic pain combined with their functional pain outcomes could enable pathological pain subtype classification by artificial neural networks. As a result, a simple and innovative clinical decision support method has been developed that combines MALDI-TOF MS serum spectra and pain evaluation with its subsequent data analysis by artificial neural networks and allows the identification and classification of pathological pain subtypes in experimental models with a high level of specificity.

Characterizing shared and distinct symptom clusters in common chronic conditions through natural language processing of nursing notes

Data-driven characterization of symptom clusters in chronic conditions is essential for shared cluster detection and physiological mechanism discovery. This study aims to computationally describe symptom documentation from electronic nursing notes and compare symptom clusters among patients diagnosed with four chronic conditions-chronic obstructive pulmonary disease (COPD), heart failure, type 2 diabetes mellitus, and cancer. Nursing notes (N = 504,395; 133,977 patients) were obtained for the 2016 calendar year from a single medical center. We used NimbleMiner, a natural language processing application, to identify the presence of 56 symptoms. We calculated symptom documentation prevalence by note and patient for the corpus. Then, we visually compared documentation for a subset of patients (N = 22,657) diagnosed with COPD (n = 3339), heart failure (n = 6587), diabetes (n = 12,139), and cancer (n = 7269) and conducted multiple correspondence analysis and hierarchical clustering to discover underlying groups of patients who have similar symptom profiles (i.e., symptom clusters) for each condition. As expected, pain was the most frequently documented symptom. All conditions had a group of patients characterized by no symptoms. Shared clusters included cardiovascular symptoms for heart failure and diabetes; pain and other symptoms for COPD, diabetes, and cancer; and a newly-identified cognitive and neurological symptom cluster for heart failure, diabetes, and cancer. Cancer (gastrointestinal symptoms and fatigue) and COPD (mental health symptoms) each contained a unique cluster. In summary, we report both shared and distinct, as well as established and novel, symptom clusters across chronic conditions. Findings support the use of electronic health record-derived notes and NLP methods to study symptoms and symptom clusters to advance symptom science.

The Anti-Nociceptive Potential of Tulathromycin against Chemically and Thermally Induced Pain in Mice

The present study was conducted to evaluate the analgesic potential of the new triamilide macrolide antibiotic, tulathromycin, at 20 and 40 mg/kg of body weight (BW), subcutaneously against acute pain in mice. Acute pain was induced either chemically (using acetic acid-induced writhing and formalin-induced pain tests) or thermally (using hot-plate, and tail-flick tests). In the acetic acid-induced writhing test, tulathromycin induced a dose-dependent and significant decrease in the number of writhes compared with the control group. In the late phase of the formalin test, a significant decline in hind paw licking time compared with the control group was observed. In the hot-plate and tail-flick tests, tulathromycin caused a dose-dependent and significant prolongation of latency of nociceptive response to heat stimuli, compared with the control group. These findings may indicate that tulathromycin possesses significant peripheral and central analgesic potentials that may be valuable in symptomatic relief of pain, in addition to its well-established antibacterial effect.

Neural Mechanisms of Hypnosis and Meditation-Induced Analgesia: A Narrative Review

Meditation and hypnosis have both been found to attenuate pain; however, little is known about similarities and differences in the cognitive modulation of pain. Hypnotic and meditative states (e.g., mindfulness) reduce pain by sharing and overlapping multiple neuro-cognitive mechanisms, but they differ in many respects. While there are overlapping brain networks involved, the nature of these effects seems different. Both phenomena involve frontal modulation of pain-related areas. The role of the dorsolateral prefrontal cortex appears to depend, in hypnosis, on the type of suggestion given and, in meditation, on the level of practice. Whereas the anterior cingulate cortex seems to be a key node in both hypnosis and meditation, the dorsolateral prefrontal cortex appears to engage in hypnosis as a function of suggestion and, in meditation, as a function of proficiency.

Pain and Function in Chronic Musculoskeletal Pain-Treating the Whole Person

Chronic pain is often associated with functional limitations that have a huge impact on patients' lives. However, despite being relatively common, chronic musculoskeletal pain is still viewed by some as a symptom of another disease rather than its own condition, and is therefore poorly addressed. This is compounded by other challenges in the field, including education gaps for both healthcare professionals and patients, a lack of universal and comprehensive assessment tools, poor societal perceptions of chronic pain, and the current stigma around the use of opioids. Here, we review the current chronic musculoskeletal pain management landscape in the United States and offer professional insight into emerging methods that can be used to improve patient outcomes, in particular, the achievement of meaningful functional goals. This perspective incorporates our combined multidisciplinary (psychiatry, psychology, nursing, physical therapy, and general medicine) experience and insights. We believe that chronic pain is a multifactorial experience and treatment requires an integrated, multidisciplinary approach from a range of healthcare providers. For the best patient outcomes, this team should work together to assess and treat the patient as a whole, addressing their pain and also providing education, empowerment, and support to enable patients to set and achieve meaningful functional goals that will provide real improvement in their quality of life. We believe that the healthcare community should elevate the conversation around chronic musculoskeletal pain management beyond that of just pain, to encompass the meaningful benefits that improvement in functional outcomes brings to patients.

Hazards and risk assessment of heavy metals from consumption of locally manufactured painkiller drugs in Nigeria

In the informal sector of Nigeria's economy, jobs are done manually as against automation resulting in body stress and pain, hence the need for painkiller drugs. Thirty different locally manufactured painkiller drugs, with analgesic, antipyretic and anti-inflammatory effects, were randomly sampled from pharmaceutical shops within Awka in October 2016. The drugs were pulverised, sieved and ashed before digestion using conc aqua regia HCl : HNO3 (3:1), carcinogenic heavy metals (arsenic, cadmium, chromium, mercury, nicked and lead) were assayed using Varian AA240 atomic absorption spectrophotometer (AAS). Risk assessment was carried out using US EPA model. The highest levels of arsenic (0.350 mg/kg) were found in samples with code 01, 03 and 020, cadmium (0.107 mg/kg and 0.144 mg/kg) were in samples code 013 and 028, and samples 03 and 011 had chromium levels as 6.637 mg/kg and 5.298 mg/kg. Highest value of mercury (0.470 mg/kg) was in sample code 01. All the painkiller drugs have nickel in the range of 0.046-0.448 mg/kg while highest values of lead were in sample code 05, 025 and 029 as 2.47 mg/kg, 1.11 mg/kg and 1.16 mg/kg. Non-cancer risk ranged as As (Nd -1.60 × 10-3), Cd (Nd-1.97 × 10-4), Cr (Nd-6.06 × 10-6), Hg (Nd-2.15 × 10-4), Ni (9.93 × 10-6-3.34 × 10-5) and Pb (Nd-4.36 × 10-4) while the cancer risk were As (Nd-1.63 × 10-7), Cd (Nd-4.45 × 10-9), Cr (Nd-1.56 × 10-7), Hg (Nd -1.53 × 10-9), Ni (1.50 × 10-10 -1.46 × 10-9) and Pb (Nd-8.82 × 10-9). The total cancer risk (TCR) and total non-cancer risk (TNCR) for all the heavy metals were in the range of 7.21 × 10-13-1.25 × 10-10 and 1.51 × 10-7-5.56 × 10-5 respectively. The TCR was below 1 × 10-6 -1 × 10-4 range while TNCR for heavy metals was below 1; the values established by US EPA. In conclusion, continuous consumption of locally Nigerian made painkiller drugs may expose the subjects to heavy metal toxicity.

Acute administration of levetiracetam in tonic pain model modulates gene expression of 5HT1A and 5HT7 receptors in the thalamus of rats (Rattus norvergicus)

The nociceptive effect of Levetiracetam (LEV) on the expression of 5-HT_1A and 5-HT₇ receptors found in the thalamus was evaluated. Thirty-six male rats (Wistar) were randomized into six groups: in the Control group without treatment; LEV50 group LEV was administered in a single dose of 50 mg/kg i.g.; in the LEV300 group LEV dose of 300 mg/kg i.g.; in the FORMALIN group the formalin test was performed; in the LEV50/FORMALIN group LEV dose of 50 mg/kg i.g and the formalin test was performed; in the LEV300/FORMALIN group LEV dose of 300 mg/kg i.g and the formalin test was performed, subsequently the thalamus was dissected in all groups. In the formalin tests LEV exhibited an antinociceptive effect in the LEV300/FORMALIN group (p < 0.05) and a pronociceptive effect in the LEV50/FORMALIN group (p < 0.001). The results obtained by Real-time PCR confirmed the expression of the 5-HT_1A and 5-HT₇ receptors in the thalamus, 5-HT_1A receptors increased significantly in the FORMALIN group and the LEV300/FORMALIN group (p < 0.05). 5-HT7 receptors are only over expressed at a dose of 300 mg/Kg of LEV with formalin (p < 0.05). This suggests that LEV modulates the sensation of pain by controlling the expression of 5-HT_1A and 5-HT₇ in a tonic pain model, and that changes in the expression of 5-HT_1A and 5-HT₇ receptors are associated with the sensation of pain, furthermore its possibility to be used in clinical treatments for pain.

Endoplasmic reticulum-mitochondria interplay in chronic pain: The calcium connection

Chronic pain is a debilitating condition that affects roughly a third to a half of the world's population. Despite its substantial effect on society, treatment for chronic pain is modest, at best, notwithstanding its side effects. Hence, novel therapeutics are direly needed. Emerging evidence suggests that calcium plays an integral role in mediating neuronal plasticity that underlies sensitization observed in chronic pain states. The endoplasmic reticulum and the mitochondria are the largest calcium repositories in a cell. Here, we review how stressors, like accumulation of misfolded proteins and oxidative stress, influence endoplasmic reticulum and mitochondria function and contribute to chronic pain. We further examine the shuttling of calcium across the mitochondrial-associated membrane as a mechanism of cross-talk between the endoplasmic reticulum and the mitochondria. In addition, we discuss how endoplasmic reticulum stress, mitochondrial impairment, and calcium dyshomeostasis are implicated in various models of neuropathic pain. We propose a novel framework of endoplasmic reticulum-mitochondria signaling in mediating pain hypersensitivity. These observations require further investigation in order to develop novel therapies for chronic pain.

Glycine transporter inhibitors: A new avenue for managing neuropathic pain

Interneurons operating with glycine neurotransmitter are involved in the regulation of pain transmission in the dorsal horn of the spinal cord. In addition to interneurons, glycine release also occurs from glial cells neighboring glutamatergic synapses in the spinal cord. Neuronal and glial release of glycine is controlled by glycine transporters (GlyTs). Inhibitors of the two isoforms of GlyTs, the astrocytic type-1 (GlyT-1) and the neuronal type-2 (GlyT-2), decrease pain sensation evoked by injuries of peripheral sensory neurons or inflammation. The function of dorsal horn glycinergic interneurons has been suggested to be reduced in neuropathic pain, which can be reversed by GlyT-2 inhibitors (Org-25543, ALX1393). Several lines of evidence also support that peripheral nerve damage or inflammation may shift glutamatergic neurochemical transmission from N-methyl-D aspartate (NMDA) NR1/NR2A receptor- to NR1/NR2B receptor-mediated events (subunit switch). This pathological overactivation of NR1/NR2B receptors can be reduced by GlyT-1 inhibitors (NFPS, Org-25935), which decrease excessive glycine release from astroglial cells or by selective antagonists of NR2B subunits (ifenprodil, Ro 25-6981). Although several experiments suggest that GlyT inhibitors may represent a novel strategy in the control of neuropathic pain, proving this concept in human beings is hampered by lack of clinically applicable GlyT inhibitors. We also suggest that drugs inhibiting both GlyT-1 and GlyT-2 non-selectively and reversibly, may favorably target neuropathic pain. In this paper we overview inhibitors of the two isoforms of GlyTs as well as the effects of these drugs in experimental models of neuropathic pain. In addition, the possible mechanisms of action of the GlyT inhibitors, i.e. how they affect the neurochemical and pain transmission in the spinal cord, are also discussed. The growing evidence for the possible therapeutic intervention of neuropathic pain by GlyT inhibitors further urges development of drugable compounds, which may beneficially restore impaired pain transmission in various neuropathic conditions.

Economic Impact of Adherence to Pain Treatment Guidelines in Chronic Pain Patients

Objectives

This research compared health care resource use (HCRU) and costs for pharmacotherapy prescribing that was adherent vs nonadherent to published pain management guidelines. Conditions included osteoarthritis (OA) and gout (GT) for nociceptive/inflammatory pain, painful diabetic peripheral neuropathy (pDPN) and post-herpetic neuralgia (PHN) for neuropathic pain, and fibromyalgia (FM) for sensory hypersensitivity pain.

Methods

This retrospective cohort study used claims from MarketScan Commercial and Medicare Databases identifying adults newly diagnosed with OA, GT, pDPN, PHN, or FM during July 1, 2006, to June 30, 2013, with 12-month continuous coverage before and after initial (index) diagnosis. Patients were grouped according to their pharmacotherapy pattern as adherent, nonadherent, or “unsure” according to published pain management guidelines using a claims-based algorithm. Adherent and nonadherent populations were compared descriptively and using multivariate statistical analyses for controlling bias.

Results

Final cohort sizes were 441,465 OA, 76,361 GT, 10,645 pDPN, 4,010 PHN, and 150,321 FM, with adherence to guidelines found in 51.1% of OA, 25% of GT, 59.5% of pDPN, 54.9% of PHN, and 33.5% of FM. Adherent cohorts had significantly (P < 0.05) fewer emergency department (ED) visits and lower proportions with hospitalizations or ED visits. Mean health care costs increased following diagnosis across all conditions; however, adherent cohorts had significantly lower increases in adjusted costs pre-index to postindex (OA $5,286 vs $9,532; GT $3,631 vs $7,873; pDPN $9,578 vs $16,337; PHN $2,975 vs $5,146; FM $2,911 vs $3,708; all P < 0.001; adherent vs nonadherent, respectively).

Conclusions

Adherence to pain management guidelines was associated with significantly lower HCRU and costs compared with nonadherence to guidelines.

Parameters of vibration stimulation for the relief of pain of different origins and locations

The use of vibration stimulation in alleviating pain is an issue appearing more and more often in modern rehabilitation. The aim of the work was to review literature regarding the therapeutic usage of vibrations in analgesic activity. Searches based on the effect of alleviating pain with the help of vibrotherapy in the therapy of diseases of various origins and localizations, as well as with various physical therapy treatments and modalities. The most important parameters were determined, such as: frequency, amplitude, places of application, and exposure time, and were described on the basis of selected tests. Both the Polish and English-language literature has been discussed. Most of the studies were English-language (over 93%). The searches were carried out among the following databases: Medline, Embase, Cochrane, ScienceDirect, PubMed, IEEE Xplore, Wiley Online Library. The key words used were: pain, vibration, WBV, analgesics. The mentioned sources were qualified on the basis of: availability, data verification, selection of research material and regularity of update. While acute pain is, by definition, a short and self-limiting process, chronic pain begins to dominate life and concerns the patient and his/her family. In addition to significant deterioration in quality of life, chronic pain imposes a large financial burden. The use of vibrotherapy can be a solution. Therefore, it is proposed to further analyse the parameters of vibrotherapy in analgesic activity, which may lay the foundation for "personalized pain relief medicine", which will clearly define the standards of vibrational therapy parameters. pain, vibration, WBV, analgesics

Augmenting the antinociceptive effects of nicotinic acetylcholine receptor activity through lynx1 modulation

Neuronal nicotinic acetylcholine receptors (nAChRs) of the cholinergic system have been linked to antinociception, and therefore could be an alternative target for pain alleviation. nAChR activity has been shown to be regulated by the nicotinic modulator, lynx1, which forms stable complexes with nAChRs and has a negative allosteric action on their function. The objective in this study was to investigate the contribution of lynx1 to nicotine-mediated antinociception. Lynx1 contribution was investigated by mRNA expression analysis and electrophysiological responses to nicotine in the dorsal raphe nucleus (DRN), a part of the pain signaling pathway. In vivo antinociception was investigated in a test of nociception, the hot-plate analgesia assay with behavioral pharmacology. Lynx1/α4β2 nAChR interactions were investigated using molecular dynamics computational modeling. Nicotine evoked responses in serotonergic and GABAergic neurons in the DRN are augmented in slices lacking lynx1 (lynx1KO). The antinociceptive effect of nicotine and epibatidine is enhanced in lynx1KO mice and blocked by mecamylamine and DHβE. Computer simulations predict preferential binding affinity of lynx1 to the α:α interface that exists in the stoichiometry of the low sensitivity (α4)₃(β2)₂ nAChRs. Taken together, these data point to a role of lynx1 in mediating pain signaling in the DRN through preferential affinity to the low sensitivity α4β2 nAChRs. This study suggests that lynx1 is a possible alternative avenue for nociceptive modulation outside of opioid-based strategies.

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.

The Expanding Therapeutic Utility of Botulinum Neurotoxins

Botulinum neurotoxin (BoNT) is a major therapeutic agent that is licensed in neurological indications, such as dystonia and spasticity. The BoNT family, which is produced in nature by clostridial bacteria, comprises several pharmacologically distinct proteins with distinct properties. In this review, we present an overview of the current therapeutic landscape and explore the diversity of BoNT proteins as future therapeutics. In recent years, novel indications have emerged in the fields of pain, migraine, overactive bladder, osteoarthritis, and wound healing. The study of biological effects distal to the injection site could provide future opportunities for disease-tailored BoNT therapies. However, there are some challenges in the pharmaceutical development of BoNTs, such as liquid and slow-release BoNT formulations; and, transdermal, transurothelial, and transepithelial delivery. Innovative approaches in the areas of formulation and delivery, together with highly sensitive analytical tools, will be key for the success of next generation BoNT clinical products.

Expectations towards participation in easily accessible pain management interventions: a qualitative study

BACKGROUND

People with chronic pain use a range of healthcare services, but they also report a high degree of dissatisfaction with treatments. One reason for dissatisfaction might be participants' expectations towards treatments. The aim of this study was to explore expectations of people with chronic pain towards participation in easily accessible pain management interventions delivered in public primary care.

METHODS

A qualitative study using semi-structured individual face-to-face interviews with 21 informants. The informants were recruited among participants enrolled in a randomised controlled trial on the effect of an easily accessible self-management course for people with chronic pain. The data were analysed thematically using Systematic Text Condensation.

RESULTS

Having experienced pain for a long time, there was no specific expectation of a cure or a significant alleviation of the pain. The informants' expectations mainly concerned a hope that participation could lead to a better everyday life. The informants said that hope was important as it motivated them to keep going and continue self-care activities. The hope acted as a driving force towards trying new interventions and maintaining motivation to do activities they experienced as beneficial. Both concrete aspects of the current intervention and an understanding of what interventions in general could offer contributed to the informants hope. The expectations centred about the interventions being something new, as they had not previously tried this service, an opportunity to gain and reinforce skills, to help them continue to grow as a person, to meet others in similar situations, and to access professional support in an easy manner. Participating in interventions provided by healthcare services was seen by some as an act of self-care, where they did something active to manage their health.

CONCLUSIONS

Expectations towards the interventions were related to a hope for participation leading to a better everyday life. The role of hope for peoples' motivation to self-care implies that service providers should be aware of and help to maintain hope for a better everyday life. The importance of social support as part of self-care should be acknowledged when developing interventions targeting chronic pain.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02531282 . Registered on August 21 2015.

Anti-inflammatory and analgesic activities of solvent fractions of the leaves of Moringa stenopetala Bak. (Moringaceae) in mice models

Background

Many people still experience pain and inflammation regardless of the available drugs for treatments. In addition, the available drugs have many side effects, which necessitated a quest for new drugs from several sources in which medicinal plants are the major one. This study evaluated the analgesic and anti- inflammatory activity of the solvent fractions of Moringa stenopetala in rodent models of pain and inflammation.

Methods

Successive soxhlet and maceration were used as methods of extractions using solvents of increasing polarity; chloroform, methanol and water. Swiss albino mice models were used in radiant tail flick latency, acetic acid induced writhing and carrageenan induced paw edema to assess the analgesic and anti-inflammatory activities. The test groups received different doses (100 mg/kg, 200 mg/kg and 400 mg/kg) of the three fractions (chloroform, methanol and aqueous). The positive control groups received morphine (20 mg/kg) or aspirin (100 mg/kg or 150 mg/kg) based on the respective models. The negative control groups received the 10 ml/kg of vehicles (distilled water or 2% Tween 80).

Results

In all models, the chloroform fraction had protections only at a dose of 400 mg/kg. However, the methanol and aqueous fraction at all doses have shown significant central and peripheral analgesic activities with a comparable result to the standards. The aqueous and methanol fractions significantly reduced carrageenan induced inflammation in a dose dependent manner, in which the highest reduction of inflammation was observed in aqueous fraction at 400 mg/kg.

Conclusion

This study provided evidence on the traditionally claimed uses of the plant in pain and inflammatory diseases, and Moringa stenopetala could be potential source for development of new analgesic and anti-inflammatory drugs.

14-O-Methylmorphine: A Novel Selective Mu-Opioid Receptor Agonist with High Efficacy and Affinity

14-O-methyl (14-O-Me) group in morphine-6-O-sulfate (M6SU) or oxymorphone has been reported to be essential for enhanced affinity, potency and antinociceptive effect of these opioids. Herein we report on the pharmacological properties (potency, affinity and efficacy) of the new compound, 14-O-methylmorphine (14-O-MeM) in in vitro. Additionally, we also investigated the antinociceptive effect of the novel compound, as well as its inhibitory action on gastrointestinal transit in in vivo. The potency and efficacy of test compound were measured by [³⁵S]GTPγS binding, isolated mouse vas deferens (MVD) and rat vas deferens (RVD) assays. The affinity of 14-O-MeM for opioid receptors was assessed by radioligand binding and MVD assays. The antinociceptive and gastrointestinal effects of the novel compound were evaluated in the rat tail-flick test and charcoal meal test, respectively. Morphine, DAMGO, Ile^5,6 deltorphin II, deltorphin II and U-69593 were used as reference compounds. 14-O-MeM showed higher efficacy (E_max) and potency (EC₅₀) than morphine in MVD, RVD or [³⁵S]GTPγS binding. In addition, 14-O-MeM compared to morphine showed higher affinity for μ-opioid receptor (MOR). In vivo, in rat tail-flick test 14-O-MeM proved to be stronger antinociceptive agent than morphine after peripheral or central administration. Additionally, both compounds inhibited the gastrointestinal peristalsis. However, when the antinociceptive and antitransit doses for each test compound are compared, 14-O-MeM proved to have slightly more favorable pharmacological profile. Our results affirm that 14-O-MeM, an opioid of high efficacy and affinity for MOR can be considered as a novel analgesic agent of potential clinical value.

Reliability and validity of the Chinese version of the Readiness for Hospital Discharge Scale-Parent Form in parents of preterm infants

Background

The Readiness for Hospital Discharge Scale (RHDS)−Parent Form shows satisfactory reliability and validity to assess the readiness of parents to take care of their children discharged from hospitals in Western countries. However, the reliability and validity of this instrument has not been evaluated in Chinese populations.

Objectives

Evaluate the psychometric features of the RHDS−Parent Form among Chinese parents of preterm infants.

Methods

The RHDS−Parent Form was translated into a Chinese version following an international instrument translation guideline. A total of 168 parents with preterm infants were recruited from the neonatal intensive care units of two tertiary-level hospitals in China. The internal consistency of this measure was assessed using the Cronbach's α coefficient; confirmatory factor analysis was conducted to evaluate the construct validity; and Pearson correlation coefficient was used to report the convergent validity.

Results

The Chinese version of RHDS (C-RHDS)−Parent Form included 22 items with 4 subscales, accounting for 56.71% of the total variance. The C-RHDS−Parent Form and its subscales showed good reliability (Cronbach's α values 0.78–0.92). This measure and its subscales showed positive correlations with the score of Quality of Discharge Teaching Scale.

Conclusion

The factor structure of C-RHDS−Parent Form is partially consistent with the original English version. Future studies are needed to explore the factors within this measure before it is widely used in Chinese clinical care settings.

Expectations, effect and experiences of an easily accessible self-management intervention for people with chronic pain: study protocol for a randomised controlled trial with embedded qualitative study

BACKGROUND

People struggling with chronic pain may benefit from different types of non-pharmacological interventions such as self-management courses. Self-management courses aim to increase participants' skills and knowledge in managing chronic conditions. Community health-care services in Norway have increasingly established Healthy Life Centres (HLCs) to offer easily accessible interventions to people in need of support to better handle a life with chronic illness. The aim of this trial is to investigate the expectations, effect and experience of an easily accessible, group-based self-management course delivered at a HLC for people with chronic pain.

METHODS/DESIGN

This is an open pragmatic two-armed randomised controlled trial with an embedded qualitative study. The intervention is a self-management course comprising education, discussions, exchange of experiences between the participants, and physical movement exercises. The control group is offered a drop-in outdoor physical activity. The intervention period is 6 weeks. The primary outcome is patient activation measured by the patient activation measure (PAM). The secondary outcomes include measures of self-efficacy, pain and quality of life. Data will be collected at baseline, and after 3, 6 and 12 months. Using a mixed linear model, the number needed in each arm to achieve a power of 80 % becomes 55. To allow for dropout, the aim is to include 120 participants. Analysis will be done using mixed linear models. In the embedded qualitative study, we will perform semi-structured face-to-face interviews with a sample from both trial arms before randomisation and after 3 and 12 months. The topics elaborated will be motivation for participation and experiences with the activity related to possible changes in managing and coping with chronic pain.

DISCUSSION

There is need for more knowledge on interventions delivering self-care support in an easily accessible way that aim to reach those in need of this kind of health service. This trial will produce important knowledge on the effect and the experiences of participants in such an easily accessible self-management course delivered in Norwegian public primary care.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02531282 . Registered on 21 August 2015.

Predictive factors associated with success and failure for Calmare (Scrambler) therapy: a multicenter analysis

OBJECTIVE

Calmare (Scrambler) therapy is a novel therapeutic modality that purports to provide pain relief by "scrambling" afferent pain signals and replacing them with "non-pain" information through conventional lines of neural transmission. The goal of this study is to identify which factors are associated with treatment outcome for Calmare therapy.

METHODS

Data were garnered from 3 medical centers on 147 patients with various pain conditions who underwent a minimum of either 3 Calmare therapies on consecutive days or 5 therapies overall. A successful outcome was predefined as ≥50% pain relief on a 0 to 10 numerical rating scale that persisted for longer than 1 month after the last treatment. Variables evaluated for their association with outcome included age, sex, study site, baseline pain score, etiology, type of pain, diagnosis, treatment compliance, coexisting psychopathology, opioid use, antidepressant use, and membrane stabilizer use.

RESULTS

Overall, the success rate was 38.1%. Variables found to be associated with a positive outcome in multivariate logistic regression included the presence of neuropathic (OR=24.78; 95% CI, 2.47-248.97; P=0.006) or mixed (OR=10.52; 95% CI, 1.09-101.28; P=0.042) pain, and treatment at either Walter Reed (OR=6.87; 95% CI, 1.60-29.51; P=0.010) or Seoul National University (OR=12.29; 95% CI, 1.73-87.43; P=0.012). Factors that correlated with treatment failure were disease (OR=0.04; 95% CI, 0.002-0.59; P=0.020) or traumatic/surgical etiologies (OR=0.05; 95% CI, 0.005-0.56; P=0.015) and antidepressant use (OR=0.47; 95% CI, 0.18-1.02; P=0.056).

CONCLUSIONS

A neuropathic or mixed neuropathic-nociceptive pain condition was associated with a positive treatment outcome. Investigators should consider these findings when developing selection criteria in clinical trials designed to determine the efficacy of Calmare therapy.

The Role of Regulatory Transporters in Neuropathic Pain

Neuropathic pain arises from an injury or disease of the somatosensory nervous system rather than stimulation of pain receptors. As a result, the fine balance between excitation and inhibition is perturbed leading to hyperalgesia and allodynia. Various neuropathic pain models provide considerable evidence that changes in the glutamatergic, GABAergic, and monoaminergic systems. Neurotransmitter reuptake transporter proteins have the potential to change the temporal and spatial profile of various neurotransmitters throughout the nervous system. This, in turn, can affect the downstream effects of these neurotransmitters and hence modulate pain. This chapter explores various reuptake transporter systems and implicates their role in pain processing. Understanding the transporter systems will enhance drug discovery targeting different facets of neuropathic pain.

A Correlative Relationship Between Chronic Pain and Insulin Resistance in Zucker Fatty Rats: Role of Downregulation of Insulin Receptors

Epidemiological studies and meta-analyses report a strong relationship between chronic pain and abnormalities in glucose metabolism, but the exact relationship between chronic pain and insulin resistance in type 2 diabetes (T2D) remains unknown. Using a model of neuropathic thermal and tactile hypersensitivity induced by chronic constriction injury (CCI) of the sciatic nerve in Zucker Diabetic Fatty (ZDF) and Zucker Lean (ZL) littermates, we compared the recovery period of hypersensitivity and the progression of T2D and studied the possible involvement of insulin receptors (IRs) in the comorbidity of these 2 conditions. We found that the nociceptive thresholds to thermal and mechanical stimulation in naive ZDF rats were lower than in ZL littermates at 6 weeks of age. Although ZDF and ZL rats developed thermal and tactile hypersensitivity after CCI, it took a longer time nociceptive sensitivity to be restored in ZDF rats. Nerve injury accelerated the progression of T2D in ZDF rats, shown by an earlier onset of hyperglycemia, more severe hyperinsulinemia, and a higher concentration of glycosylated hemoglobin Alc 6 weeks after CCI, compared with those in naive ZDF and ZL rats. IR-immunoreactive cells were located across the central nervous system and skeletal muscles. In the central nervous system, IR coexpressed with a neuronal marker (neuronal nuclei) but not a glial marker (glial fibrillary acidic protein). There was a low level of IR expression in skeletal muscles of naive ZDF rats. In contrast, CCI reduced the IR expression in skeletal muscles as well as the ipsilateral spinal cord, primarily in the dorsal horn. In conclusion, our data suggest that the relationship between insulin resistance and chronic pain in ZDF rats is bidirectional and an impaired IR signaling system might be implicated in this reciprocal relationship.

PERSPECTIVE

Nerve injuries in genetically susceptible individuals might accelerate the development of insulin resistance as in T2D. A downregulated expression of IRs in the skeletal muscle innervated by the injured nerve is one of the underlying mechanisms.

Therapeutic evaluation of "Ayush Tulsi Jiwan Plus" oil for chronic musculoskeletal pain relief

Background:

Chronic pain of musculoskeletal origin is a very common symptom and has major effect on the physical, mental, and economic aspects of the patients. There is always a crave among physicians and patients for effective analgesic, curable preparation that can be locally applied.

Aim:

The aim of this study is to assess the efficacy and safety of “Ayush Tulsi Jiwan Plus” oil in chronic pain management of musculoskeletal origin.

Materials and Methods:

Fifty patients of chronic musculoskeletal pain of unknown origin of mild to moderate condition were advised to apply “Ayush Tulsi Jiwan Plus” oil locally twice daily for 6 weeks and examined weekly. After completion of the treatment, the efficacy of the therapy was assessed on the basis of the subjective criteria such as perception of pain, tenderness, swelling, and joint mobility.

Results:

In this study, mean baseline score versus last visit score of pain (2.84 ± 0.68 vs. 1.33 ± 0.76), tenderness (1.64 ± 0.74 vs. 0.36 ± 0.56), and swelling (0.64 ± 0.85 vs. 0.38 ± 0.66) was significantly decreased, and also clinical improvement was seen in the study participants along with no evidence of adverse drug reactions.

Conclusion:

The analysis of the overall effect of this “Ayush Tulsi Jiwan Plus” oil preparation was found efficacious and topically safe in chronic pain conditions. However, further study will be required with larger sample size and in heterogeneous population to elicit long-term effect of this polyherbal preparation.

Correlations Between Electrically Quantified Pain Degree, Subjectively Assessed Visual Analogue Scale, and the McGill Pain Questionnaire: A Pilot Study

Objective

To evaluate the clinical utility of the electrically calculated quantitative pain degree (QPD) and to correlate it with subjective assessments of pain degree including a visual analogue scale (VAS) and the McGill Pain Questionnaire (MPQ).

Methods

We recruited 25 patients with low back pain. Of them, 21 patients suffered from low back pain for more than 3 months. The QPD was calculated using the PainVision (PV, PS-2100; Nipro Co., Osaka, Japan). We applied electrodes to the medial forearm of the subjects and the electrical stimulus was amplified sequentially. Minimum perceived current (MPC) and pain equivalent current (PEC) were defined as minimum electrical stimulation that could be sensed by the subject and electrical stimulation that could trigger actual pain itself. To eliminate individual differences, we defined QPD as the following: QPD=PEC-MPC/MPC. We scored pre-treatment QPD three times at admission and post-treatment QPD once at discharge. The VAS, MPQ, and QPD were evaluated and correlations between the scales were analyzed.

Results

Result showed significant test-retest reliability (ICC=0.967, p<0.001) and the correlation between QDP and MPQ was significant (at admission SRCC=0.619 and p=0.001; at discharge SRCC=0.628, p=0.001). However, the correlation between QPD and VAS was not significant (at admission SRCC=0.240, p=0.248; at discharge SRCC=0.289, p=0.161).

Conclusion

Numerical values measured with PV showed consistent results with repeated calculations. Electrically measured QPD showed an excellent correlation with MPQ but not with VAS. These results demonstrate that PV is a significantly reliable device for quantifying the intensity of low back pain.

The Application of Tensegrity Massage in a Professionally Active Musician - Case Report

PURPOSE

The purpose of our study was to present options for the application of tensegrity massage to manage pain caused by the overload of soft tissues in musicians.

DESIGN

Tensegrity massage was applied to a 34-year-old male violinist.

METHODS

The methodology included a correct positioning and tensegrity massage with individually designed procedure.

FINDINGS

After therapy, the patient achieved complete pain relief, and relaxation of muscles in the shoulder girdle and free part of the upper arm. The analgesic effect lasted for 6 months after the end of therapy.

CONCLUSIONS

Massage is an effective method in eliminating pain caused by the overload of soft tissues. If used regularly before physical effort, it can prevent muscle overload.

CLINICAL RELEVANCE

The presented massage procedure is an effective therapy in pain caused by the overload of soft tissues in musicians and it can be one of the elements of complex physiotherapy in active musicians.