Pain

Persons with chronic musculoskeletal pain may be hypervigilant for pain-related cues which, paradoxically, may be maintaining their pain. Several randomized controlled trials have assessed whether a modified dot-probe protocol (i.e., attention bias modification; ABM) reduces chronic pain- and pain-related symptoms in persons with several diagnoses, including fibromyalgia. Scalability and economic efficiency potentiates the appeal of ABM protocols; however, research results have been mixed, with only some studies evidencing significant symptom gains from ABM and some evidencing gains for the control group...

Most studies of diabetic polyneuropathy (DPN) and painful DPN are conducted in persons with longstanding diabetes. This cross-sectional study aimed to estimate the prevalence of DPN and painful DPN, important risk factors, and the association with mental health in recently diagnosed type 2 diabetes. A total of 5,514 (82%) patients (median diabetes duration 4.6 years) enrolled in the Danish Centre for Strategic Research in Type 2 Diabetes cohort responded to a detailed questionnaire on neuropathy and pain. A score ≥ 4 on the MNSI questionnaire determined possible DPN whereas pain presence in both feet together with a score ≥ 3 on the DN4 questionnaire determined possible painful DPN...

Complex regional pain syndrome (CRPS) develops after limb injury, with persistent pain and deficits in movement frequently co-occurring. The striatum is critical for mediating multiple mechanisms that are often aberrant in CRPS, which includes sensory and pain processing, motor function and goal-directed behaviors associated with movement. Yet much remains unknown with regards to the morphological and functional properties of the striatum and its sub-regions in this disease. Thus, we investigated 20, patients (15 female, age 58 ± 9 years, right-handed) diagnosed with chronic (6+ months of pain duration) CRPS in the right hand and 20 matched, healthy controls with anatomical and resting-state, functional magnetic resonance imaging (fMRI)...

The complex mechanisms underlying migraine are not entirely understood. It has been suggested that descending endogenous pain modulation is an important contributing factor, although research is controversial. A frequently used method to quantify the inhibitory pain modulation system is offset analgesia (OA), defined as a disproportionally large decrease in pain perception in response to a small decrease of painful stimulation. The aim of this study is to evaluate the OA response in patients with migraine and healthy controls, measured at the forehead (trigeminal, V1) and forearm (extra-trigeminal)...

Altered pro-nociceptive and anti-nociceptive mechanisms are often implicated in painful conditions and have been increasingly studied over the past decade. For some painful conditions alterations are well-established, but in low back pain (LBP) populations there remains considerable debate whether these mechanisms are altered. The present systematic review aimed to address this issue by identifying studies assessing Conditioned Pain Modulation (CPM) and/or Temporal Summation of Pain (TSP) in LBP patients, comparing to either a healthy control group or using a method with reference data available...

Chronic neuropathic pain (NP) is debilitating and impacts sleep health and quality of life. Treatment with gabapentinoids (GB) has been shown to reduce pain, but its effects on sleep health have not been systematically evaluated. The objective of this systematic review and meta-analysis was to assess the relationship between GB therapy dose and duration on sleep quality, daytime somnolence, and intensity of pain in patients with neuropathic pain. Subgroup comparisons were planned for high vs. low dose GB, where 300mg per day or more of pregabalin was used to classify high-dose therapy...

No abstract text is available yet for this article.

Pain-related fear and avoidance are increasingly demonstrated to play an important role in adult and childhood chronic pain. The Fear of Pain Questionnaire for Children (FOPQC) is a 24-item measure of pain-related fear-avoidance in youth that has demonstrated good indices of reliability and validity, treatment responsiveness, and associations with brain circuitry alterations. This study describes the development and psychometric examination of the FOPQC-SF, a short form of the original measure. We selected 10 items for the short form that best represented the content and two-factor (Fear and Avoidance) structure of the original measure from a cohort of 613 youth (Mage = 14...

Central neuropathic pain (CNP) after spinal cord injury (SCI) is debilitating and immensely impacts the individual. CNP is relatively resistant to treatment administered after it develops, perhaps owing to irreversible pathological processes. Although preemptive treatment may overcome this shortcoming, its administration necessitates screening patients with clinically relevant biomarkers that could predict CNP early post-SCI. The aim was to search for such biomarkers by measuring pro-nociceptive and for the first time, anti-nociceptive indices early post-SCI...

Pain-related fear is typically associated with avoidance behavior and pain-related disability in youth with chronic pain. Youth with elevated pain-related fear have attenuated treatment responses, thus targeted treatment is highly warranted. Evidence supporting graded in-vivo exposure treatment (GET) for adults with chronic pain is considerable, but just emerging for youth. The current investigation represents the first sequential replicated and randomized single-case experimental phase design with multiple measures evaluating GET for youth with chronic pain, entitled GET Living...

In Complex Regional Pain Syndrome (CRPS), tactile sensory deficits have motivated the therapeutic use of sensory discrimination training. However, the hierarchical organisation of the brain is such that low-level sensory processing can be dynamically influenced by higher-level knowledge, e.g. knowledge learnt from statistical regularities in the environment. It is unknown whether the learning of such statistical regularities is impaired in CRPS. Here, we employed a hierarchical Bayesian model of predictive coding to investigate statistical learning of tactile-spatial predictions in CRPS...

Despite evidence of broad impact on daily functioning in adolescence, little is known regarding the life course effects of childhood chronic pain. This is the first nationally representative study to characterize the disruptive impact of chronic pain in adolescence on key educational, vocational, and social outcomes in young adulthood (12 years later). Data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) was used, including 3,174 youth with chronic pain and 11,610 without chronic pain...

No abstract text is available yet for this article.

Two recent studies suggest that experimental pain sensitivity is associated with low-grade systemic inflammation. However, only two biomarkers have been identified and the studies were conducted in adult individuals where confounding effects of comorbid diseases cannot be excluded. We therefore tested associations between pain sensitivity and 119 inflammation-related serum biomarkers in 827 healthy adolescents (15-19 years) in the population-based Tromsø Study: Fit Futures. The main outcome measure was cold-pressor pain tolerance (CPT), tested by placing the dominant hand in circulating cold (3°C) water for a maximum of 105s...

Patients with radicular low back pain (radicular LBP, sciatica) frequently describe their pain as "shooting" or "radiating". The dictionary meaning of these words implies rapid movement, and indeed, many sufferers report feeling pain moving rapidly from the lower back or buttock into the leg. But others do not. Moreover, the sensation of movement is paradoxical; it is neither predicted nor accounted for by current ideas about the pathophysiology of radicular LBP. We have employed a structured questionnaire to evaluate the sensory qualities associated with "shooting" and "radiating" in 155 patients, 98 with radicular LBP and 57 with trigeminal neuralgia (TN), a second chronic pain condition in which shooting/radiating are experienced...

African Americans experience an increased burden of motor vehicle collision (MVC), post-MVC musculoskeletal pain (MSP) and Vitamin D insufficiency. In this prospective multicenter study, we tested the hypothesis that African Americans (n=133) presenting to the ED after MVC with low peritraumatic Vitamin D levels would have worse chronic MSP outcomes compared to individuals with sufficient Vitamin D. Vitamin D levels were assessed in the early aftermath of MVC via enzyme-linked immunosorbent assay, and pain severity was assessed via the 0-10 numeric rating scale at 6 weeks, 6 months and 1 year...

Chronic pain and anxiety symptoms are frequently encountered clinically, but the neural circuit mechanisms underlying the comorbid anxiety symptoms in pain (CASP) in context of chronic pain remain unclear. Using viral neuronal tracing in mice, we identified a previously unknown pathway whereby glutamatergic neurons from layer 5 of the hindlimb primary somatosensory cortex (S1) (Glu), a well-known brain region involved in pain processing, project to GABAergic neurons in the caudal dorsolateral striatum (GABA)...

No abstract text is available yet for this article.

Patients with chronic pain often report being sensitive to pain at night before falling asleep, a time when the synchronization of cortical activity is initiated. However, how cortical activity relates to pain sensitivity is still unclear. Since sleep is characterized by enhanced cortical delta power, we hypothesized that enhanced cortical delta power may be an indicator of intensified pain. To test this hypothesis, we used pain thresholds tests, EEG/electromyogram recordings, c-Fos staining and chemogenetic and pharmacological techniques in mice...

Oxaliplatin is a cornerstone chemotherapeutic used in the treatment of colorectal cancer, the third leading cause of death in Western countries. Most side effects of this platinum-containing drug are adequately managed in the clinic, although acute and long-term neurotoxicity still severely compromises the quality of life of patients treated with oxaliplatin.We have previously demonstrated that therapeutically relevant concentrations/doses of oxaliplatin lead to a reduction in intracellular pH in mouse dorsal root ganglia neurons in vitro and in vivo and that this alteration sensitizes TRPA1 and TRPV1 channels, which most likely mediate the allodynia associated with treatment...