Is chronic pain a disease?
It was not until the twentieth century that pain was considered a disease. Before that it was managed medically as a symptom. The motivations for declaring chronic pain a disease, whether of the body or of the brain, include increasing its legitimacy as clinical problem and research focus worthy of attention from healthcare and research organizations alike. But one problem with disease concepts is that having a disease favors medical solutions and tends to reduce patient participation. We argue that chronic pain, particularly chronic primary pain (recently designated a first tier pain diagnosis in ICD 11), is a learned sta...
Source: The Journal of Pain - May 13, 2022 Category: Materials Science Authors: Jane C. Ballantyne, Mark D. Sullivan Tags: Focus Article Source Type: research

Similarities in the neuropathy phenotype of cancer survivors who received different classes of chemotherapy drugs
With the advent of platinum and taxane compounds, survival rates for some of the most common cancers have improved substantially. For both of these drug classes, the dose limiting toxicity is chemotherapy-induced peripheral neuropathy (CIPN), that occurs in 30% to 70% of cancer survivors.12, 33 CIPN is characterized by symptoms of pain, numbness, and paresthesia in the hands and feet that spread proximally in a “stocking-glove” distribution.8, 12, 35 CIPN is associated with a variety of common symptoms (e.g., sleep disturbance) and has negative effects on survivors’ quality of life (QOL). (Source: The Journal of Pain)
Source: The Journal of Pain - May 6, 2022 Category: Materials Science Authors: Christine Miaskowski, Jon D. Levine, Steven M. Paul, Bruce Cooper, Gary Abrams, Kimberly Topp, Steven Cheung, Jennifer Henderson-Sabes, Yvette P. Conley, Karin Snowberg, Emely Alfaro, Marisa Quinn, Kord M. Kober Tags: Original Reports Source Type: research

The Relationship between Pain Resilience and Back Pain Severity for Participants with Chronic Low Back Pain
Most research for chronic pain is centered around psychosocial risk factors, like pathological vulnerability. Currently, researchers are looking at the potential protective role of positive and adaptive factors on chronic pain, like pain resiliency. However, it has not been well-established what role biobehavioral factors, like weight, or sociodemographic factors, like sex or race, may have on the multisystem dimensions of pain resilience, like behavioral perseverance and cognitive-affective positivity. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Asia Wiggins Tags: Acute (to Chronic) Pain1 Source Type: research

DNA Methylation Levels in Hypothalamic-pituitary-adrenal Axis Genes Predict Chronic Pain Outcomes Following Trauma Exposure
Chronic posttraumatic musculoskeletal pain (CPTP) is a common outcome of traumatic stress exposure. Biological factors that predict risk for and mediate the development of CPTP are poorly understood. Current evidence indicates that dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis plays a substantial role in the development of CPTP. However, little is known about the molecular mechanisms that drive the association between HPA axis genes and CPTP, such as epigenetic regulatory mechanisms. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Erica Marie Branham, Ishani H. Deliwala, Matthew C. Mauck, Ying Zhao, Aaron Lee, Anthony Zannas, Lauren A. McKibben, Alex B. Spencer, Bruce A. Cairns, Megan Lechner, Teresa Danza, Michael C. Kurz, Marc-Anthony Velilla, Phyllis L. Hendry, Claire Pearson, E Tags: 2 Source Type: research

Implications For Inflammation and Host-Microbiome Interactions In Bowel Dysfunction And Pain After Spinal Cord Injury
Neurogenic bowel (NB) affects up to 60% of people with spinal cord injury (SCI) and is characterized by slow colonic transit, constipation, and chronic abdominal pain. NB rarely resolves and tends to worsen over time, making it a long-term physical and psychological challenge for people with SCI. The knowledge gap surrounding the underlying mechanisms of NB after SCI means that interventions are symptom-focused with only modest gains reported. Identifying the mechanism(s) that initiate and maintain NB after SCI is critically important to the development of evidence-based, novel therapeutic options for bowel dysfunction and...
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Adam Willits, Leena Kader, Olivia Eller, Kyle Baumbauer, Erin Young Tags: 3 Source Type: research

Early life incision induces an epigenetic modification in macrophages to drive neonatal nociceptive priming
Muscle injury evokes multiple biological responses including immune cell activation. Among these, macrophages are key players that regulate inflammation and nociception. They are also “trained” through pattern recognition and epigenetic modifications to facilitate future activity. Neonatal mechanisms of nociception are unique from that of adults but are less well studied. Basic and clinical studies agree that neonatal injury “primes” the individual, predisposing them to w orse outcomes following subsequent injury. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Adam Dourson, Anna M. Warshak, Megan C. Hofmann, Michael P. Jankowski Tags: 4 Source Type: research

Pathology activated prodrugs targeting Nrf2 to treat neuropathic pain
The antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) is a desirable therapeutic target for a broad range of pathologies, including chronic pain. However, current Nrf2 activators are limited by unwanted effects due to non-specificity, and systemic distribution and action. We aimed to overcome these long-standing issues by creating a compound that would mask the unwanted electrophilic nature of the Nrf2 activator monomethyl fumarate (MMF) until selective generation of MMF at sites of oxidative pathology associated with pain. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Jiahe Li, Thomas D. Avery, Dion J.L Turner, Fisher R. Cherry, Mohd S. Ur Rasheed, Clarissa Aguilar, Andrew J. Shepherd, Jingxian Yu, Andrew D. Abell, Peter M. Grace Tags: 5 Source Type: research

Microglia Activation Tracking across Brain Regions over the Development of Neuropathic Pain
Neuropathic pain is a chronic, debilitating condition associated with impaired cognitive, affective and sensory dimensions. One of the mechanisms underlying neuropathic pain is neuroinflammation. Microglia are resident macrophages in the central nervous system and plays an important role in setting neuroinflammation during chronic pain conditions. Microglial mechanisms of pain have been broadly studied in the spinal cord. However, brain mapping of microglial activation over the development of neuropathic pain has not been performed. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Rafael Cazuza, Michael J. Lacagnina, Peter M. Grace Tags: 6 Source Type: research

Perioperative Oxidative Stress Prospectively Predicts CRPS-Related Outcomes in the 6 months Following Total Knee Arthroplasty
This project tested whether oxidative stress (OS) related to extended tourniquet application during total knee arthroplasty (TKA) and subsequent ischemic reperfusion contributed to CRPS outcomes up to 6 month following TKA. Blood samples were obtained in 90 osteoarthritis patents (63.3% female; 95.6% Non-Hispanic White) undergoing TKA prior to tourniquet placement (T1), 45 minutes after tourniquet inflation (T2), and 15 minutes following tourniquet removal (T3). Plasma levels of F2-isoprostanes (IsoPs) and isofurans (IsoFs), the most specific measures of in vivo OS, were quantified. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Stephen Bruehl, Frederic T. Billings IV, Sara Anderson, Gregory Polkowski, Andrew Shinar, Jonathan Schildcrout, Yaping Shi, Ginger Milne, Anthony Dematteo, Puneet Mishra, R. Norman Harden Tags: 7 Source Type: research

Neighborhood Disadvantage Is Associated with Temporal Lobe Cortical Thickness in Adults with Chronic Knee Pain: Sociodemographic Differences
Findings from a multi-site study conducted by our research team previously revealed that non-Hispanic Black (NHB) adults with high chronic pain stage have thinner temporal cortex relative to their non-Hispanic White (NHW) counterparts with knee pain. Groups differ on a number of neurobiologically relevant socio/environmental factors. Mounting evidence indicates that health disparities are tied to socioeconomic resources, or lack thereof. Neighborhood disadvantage is associated with poor chronic pain outcomes and neurodegeneration. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Lisa H. Antoine, Jared J. Tanner, Kimberly T. Sibille, Roger B. Fillingim, Burel R. Goodin Tags: 8 Source Type: research

Role of Mast Cells in HIV-associated Chronic Widespread Pain
Chronic widespread pain (CWP) in people with HIV-1 (PWH) is associated with a high rate of disability and low quality of life, with prevalence estimates ranging from 25%-85%. However, the specific mechanisms that contribute to CWP in HIV are not understood. Previously we demonstrated that PWH with CWP have increased hemolysis, elevated plasma levels of cell-free heme, and attenuated levels of the heme degrading enzyme, heme oxygenase 1 (HO-1). We also found that high cell-free heme and low HO-1 were associated with hypersensitivity in animals. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Anastasiia Gryshyna, Tanima Chatterjee, Itika Arora, Sonya Heath, Burel Goodin, Saurabh Aggarwal Tags: 9 Source Type: research

Zona Incerta Modulates Pain-Associated Behaviors in Mice
In this study, we identified an inhibitory neural circuit that originates in central amygdala protein kinase C-delta (CeA-PKC δ) neurons and terminates in the ventral sector of the zona incerta (ZI), a subthalamic structure previously linked to pain processing. Behavioral experiments show that chemogenetic inhibition of GABAergic ZI neurons induces bilateral hypersensitivity in uninjured mice as well as contralateral hype rsensitivity after nerve injury. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Sudhuman Singh, Barbara Benowitz, Spring Valdivia, Omar Soler-Cede ño, Anisha P. Adke, Daniela Velasquez, Torri D. Wilson, Yarimar Carrasquillo Tags: 10 Source Type: research

Distinct Populations of Spinal Projection Neurons Mediate Divergent Functions for Pain and Sensorimotor Integration
Pain is believed to be relayed from the spinal cord to brain through two major ascending pathways. One arises largely from the superficial dorsal horn, primarily targets the parabrachial nucleus (PBN), and is thought to mediate the aversive component of pain. The other arises predominantly from the deep dorsal horn, primarily targets the rostral aspect of the ventral posterior lateral (VPL) thalamus, and is thought to mediate the discriminative component of pain. However, the precise roles of these two populations have been a subject of ongoing controversy. (Source: The Journal of Pain)
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Haichao Chen, Sarah E. Ross Tags: 11 Source Type: research

STING Expression in Peripheral Sensory Neurons Underlies Virus Recognition and Pain
Pain is an early and common symptom of viral infections, and yet we have a limited understanding about the mechanisms through which viruses induce pain. Peripheral sensory neurons are well-studied for their role in pain, and are emerging as new actors in pathogen recognition and defense. It has been reported that peripheral sensory neurons express several proteins associated with virus recognition, including the stimulator of interferon genes (STING). Although STING and interferon signaling has been recently proposed as a critical regulator of physiological pain and a promising new target for treating chronic pain, whether...
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Sanghoon Lee, Fabio Bonifacio, Arthur Silveira Prudente, Jueun Roh, Sung Jun Jung, Chul-Kyu Park, Thiago M. Cunha, Temugin Berta Tags: 12 Source Type: research

Single-Cell Analysis of Dorsal Root Ganglia Reveals Metalloproteinase Signaling in Satellite Glial Cells and Pain
Somatosensory stimuli such as touch, temperature and pain are transduced in the periphery and transmitted to the central nervous system by primary sensory neurons, which cell bodies reside in sensory ganglia such as dorsal root ganglia (DRGs). Although DRG are complex tissues with neuronal and non-neuronal cells, diversity of non-neuronal cells and their function in homeostasis and pain are still unclear. Satellite glial cells (SGCs) are among the most abundant non-neuronal cells in DRGs and tightly envelop neurons providing metabolic and trophic support, buffering extracellular ions and neurotransmitters, and enabling neu...
Source: The Journal of Pain - May 1, 2022 Category: Materials Science Authors: Arthur Silveira Prudente, Raquel Tonello, Sanghoon Lee, Cinder Cohen, Wenrui Xie, Judith Strong, Jun-Ming Zhang, Temugin Berta Tags: 13 Source Type: research