The latest medical research on Pain Medicine

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about pain medicine gathered by our medical AI research bot.

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Construction And Analysis Of The Time-Evolving Pain-Related Brain Network Using Literature Mining.

Journal of Pain

We aimed to quantitatively investigate how the neuroscience field developed over time in terms of its concept on how pain is represented in the brain and compare the research trends of pain with those of mental disorders through literature mining of accumulated published articles.

The abstracts and publication years of 137,525 pain-related articles were retrieved from the PubMed database. We defined 22 pain-related brain regions that appeared more than 100 times in the retrieved abstracts. Time-evolving networks of pain-related brain regions were constructed using the co-occurrence frequency. The state-space model was implemented to capture the trend patterns of the pain-related brain regions and the patterns were compared with those of mental disorders.

The number of pain-related abstracts including brain areas steadily increased; however, the relative frequency of each brain region showed different patterns. According to the chronological patterns of relative frequencies, pain-related brain regions were clustered into three groups: rising, falling, and consistent. The network of pain-related brain regions extended over time from localized regions (mainly including brain stem and diencephalon) to wider cortical/subcortical regions. In the state-space model, the relative frequency trajectory of pain-related brain regions gradually became closer to that of mental disorder-related brain regions.

Temporal changes of pain-related brain regions in the abstracts indicate that emotional/cognitive aspects of pain have been gradually emphasized. The networks of pain-related brain regions imply perspective changes on pain from the simple percept to the multidimensional experience. Based on the notable occurrence patterns of the cerebellum and motor cortex, we suggest that motor-related areas will be actively explored in pain studies.

Impact of daily yoga-based exercise on pain, catastrophizing, and sleep amongst individuals with fibromyalgia.

Journal of Pain

Fibromyalgia (FM) is a chronic widespread pain disorder characterized by negative affect, sleep disturbance, and fatigue. This uncontrolled pilot study investigated the efficacy of daily yoga-based exercise to improve FM symptoms and explored baseline phenotypic characteristics associated with the greatest benefit.

FM patients (n=46, with 36 completers) reported psychosocial functioning and a range of FM symptoms using validated instruments before and after participation in Satyananda yoga, which included weekly in-person pain-tailored group classes for 6 weeks and daily home yoga video practice.

Changes in FM symptoms from pre- to post-yoga were variable amongst participants. Group means for pain decreased, as reported by average daily diary and Brief Pain Inventory, with greater home practice minutes associated with a greater decrease in pain. Average daily ratings of sleep and fatigue improved. Pain catastrophizing was decreased overall, with greater change correlated to a decrease in FM symptoms. We did not observe any group mean changes in actigraphy sleep efficiency, Patient-Reported Outcomes Measurement Information System-anxiety and the Revised Fibromyalgia Impact Questionnaire. Multilevel Modeling analysis revealed a significant interaction between anxiety and catastrophizing for end-study sleep efficiency, fatigue, and pain, such that patients with higher baseline catastrophizing and lower baseline anxiety reported less pain and fatigue, and higher sleep efficiency after the sixth week of yoga practice.

This pilot study suggests that yoga may reduce pain and catastrophizing, as well as improve sleep, but these changes were modest across study participants. Greater uptake of home yoga practice as well as a phenotype of higher baseline catastrophizing combined with lower baseline anxiety were associated with greater impact. Future randomized, controlled trials comparing different types of yoga or exercise will allow determination of the most effective treatments for FM and allow closer targeting to the patients who will benefit most from them.

Co-Administered Low Doses Of Ibuprofen And Dexamethasone Produce Synergistic Antinociceptive Effects On Neuropathic Mechanical Allodynia In Rats.

Journal of Pain

The traditional analgesics used to treat neuropathic pain such as anticonvulsants, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs) lack efficacy and/or carry unpleasant side effects. The present study aimed to investigate the synergistic antinociceptive effects of co-administered low doses of ibuprofen and dexamethasone in rats with trigeminal neuropathic pain.

A Sprague-Dawley rat model for trigeminal neuropathic pain was produced using mal-positioned dental implants. The left mandibular second molar was extracted under anesthesia and replaced with a miniature dental implant to induce injury to the inferior alveolar nerve.

Monotherapy with intraperitoneal injection of high-dose ibuprofen (30 mg/kg) or dexamethasone (10 mg/kg) but not low-dose ibuprofen (1, 5, 10 mg/kg) or dexamethasone (0.01, 1 mg/kg) attenuated the neuropathic mechanical allodynia in the rats with inferior alveolar nerve injury. We examined the synergistic antinociceptive effects of co-administered ibuprofen (5 mg/kg) and dexamethasone (0.01, 0.1, 1 mg/kg). The early co-administration of ibuprofen (5 mg/kg) with dexamethasone (0.1, 1 mg/kg) on postoperative days (POD) 1-3 significantly inhibited mechanical allodynia before the pain had been established. We also observed the synergistic antinociceptive effects of the same doses the combined treatment on mechanical allodynia on POD 7-9, when the pain had already been established. The attenuation of c-fos immuno-positive cells in the ipsilateral trigeminal subnucleus caudalis after the intraperitoneal co-administration of ibuprofen (5 mg/kg) with dexamethasone (1 mg/kg) confirmed these synergistic antinociceptive effects. Moreover, the magnitude of the effects of this co-administration was comparable with that of gabapentin both before and after the pain had been established.

These results suggest that a combination of ibuprofen and dexamethasone at low doses is an alternative therapeutic strategy for neuropathic pain and provide a rationale for the use of such drug combinations in patients who are unable to tolerate high-dose monotherapy.

Pain Management In Pediatric Patients With Postural Orthostatic Tachycardia Syndrome: Current Insights.

Journal of Pain

Pediatric patients with postural orthostatic tachycardia syndrome (POTS) often present with co-occurring struggles with chronic pain (POTS+pain) th...

Cosyntropin for the Treatment of Refractory Postdural Puncture Headache in Pediatric Patients: A Retrospective Review.

Clin J Pain

Postdural puncture headache is a challenging complication of diagnostic, therapeutic, and unintentional lumbar puncture. Literature evidence supports cosyntropin as a viable noninvasive therapy for adults who have failed conservative management, but pediatric data is limited. The purpose of this retrospective chart review is to describe the use of intravenous cosyntropin for refractory pediatric postdural puncture headache at a single free-standing tertiary care pediatric hospital.

Patients who had received cosyntropin were identified. Charts were retrospectively reviewed for indication, dosing information, efficacy and side effects. Response was defined as fifty percent reduction in pain score, with a secondary efficacy measure of time to discharge after first dose.

Over a five-year period, 26 patients received 37 doses of cosyntropin. Dosing ranged from 5-15▒mcg/kg (median 10.4▒mcg/kg). There was significant reduction in pain scores after the first dose of cosyntropin (P=0.008). Eighty-one percent of patients (n=21) achieved either 50% reduction in pain or discharge within 24 hours after the first dose. Median time to 50% pain reduction in 13 patients who achieved it prior to discharge was five hours (range 1-30▒h). Median time to discharge after first dose was 20 hours (range 2-72▒h). Ten patients received more than one dose of cosyntropin. Three patients required epidural blood patch. No adverse effects related to treatment were identified.

This study suggests that while further research is warranted, cosyntropin is a potential alternative to epidural blood patch for pediatric patients with postdural puncture headache who fail conservative management.

Sleep Moderating the Relationship between Pain and Health Care Use in Youth with Sickle Cell Disease.

Clin J Pain

The purpose of the current study was to investigate the influence of sleep on the relationship between pain and health care use (HCU) in youth with sickle cell disease (SCD). It was hypothesized that poor sleep would be related to higher HCU and would strengthen the relationship between high pain frequency and more HCU among youth with SCD.

Ninety-six youth with SCD (aged 8-17▒y), and their guardians, were recruited from three regional pediatric SCD clinics. Guardians reported on the youth's pain frequency and HCU using the Structured Pain Interview for Parents, and youth wore a sleep actigraph for up to two weeks to assess sleep duration and sleep efficiency. A series of regression models were calculated with the following outcomes: emergency department visits, hospitalizations, and health care provider contacts.

Inconsistent with hypotheses, poor sleep was not directly related to HCU. Also, higher sleep duration appeared to strengthen the relationship between high pain frequency and more ED visits.

Findings suggest that good sleep may serve as protective factor for better matching pain to HCU. Results should be interpreted in the context of study limitations. Future research is needed to investigate possible mechanisms linking sleep duration to HCU in response to pain and to ascertain if sleep patterns influence the relationship between pain and other functional outcomes in youth with SCD. Clinically, these findings support the need to acknowledge and address the role that sleep plays in responding to SCD pain in pediatric populations.

A MAPP Network Case-control Study of Urological Chronic Pelvic Pain Compared With Nonurological Pain Conditions.

Clin J Pain

Limited research suggests commonalities between urological chronic pelvic pain syndromes (UCPPS) and other nonurological chronic overlapping pain conditions (COPCs) including fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome. The goal of this case-control study was to examine similarities and differences between UCPPS and these other COPCs.

As part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research (MAPP) Network, we examined 1039 individuals with UCPPS (n=424), nonurological COPCs (n=200), and healthy controls (HCs; n=415). Validated standardized measures were used to assess urological symptoms, nonurological pain symptoms, and psychosocial symptoms and traits.

Participants with UCPPS had more urological symptoms than nonurological COPCs or HCs (P<0.001); nonurological COPC group also had significantly worse urological symptoms than HCs (P<0.001). Participants with nonurological COPCs reported more widespread pain than those with UCPPS (P<0.001), yet both groups had similarly increased symptoms of anxiety, depression, negative affect, perceived stress, neuroticism, and lower levels of extraversion than HCs (P<0.001). Participants with UCPPS with and without COPCs reported more catastrophizing than those with nonurological COPCs (P<0.001).

Findings are consistent with the hypothesis of common underlying biopsychosocial mechanisms and can guide the comprehensive assessment and treatment of these conditions regardless of the primary site of pain or diagnosis. Heightened catastrophizing in UCPPS should be examined to inform psychosocial interventions and improve patient care.

Less Severe Preoperative Synovitis is Associated With Higher Self-reported Pain Intensity 12 Months After Total Knee Arthroplasty-An Exploratory Prospective Observational Study.

Clin J Pain

Synovitis is one of the possible pain generators in osteoarthritis (OA) and is associated with upregulation of proinflammatory cytokines, which can lead to worsening of the postoperative pain. This exploratory study aimed to investigate the association between perioperative synovitis and self-reported pain 12 months after total knee arthroplasty (TKA) in patients with OA.

Twenty-six knee OA patients were included in this analysis. The perioperative volume of synovitis in predefined locations was assessed by contrast-enhanced magnetic resonance imaging (CE-MRI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Perioperative synovitis was assessed histologically from biopsies of the synovium. Highest pain intensity within the last 24 hours (Visual Analog Scale, VAS, 0 to 100) was assessed before and 12 months after TKA. Patients were divided into a low-pain intensity (VAS≤30) and a high-pain intensity (VAS>30) group on the basis of 12 months postoperative VAS.

The high-pain intensity group had significantly lower perioperative contrast-enhanced-synovitis (P=0.025), DCE-synovitis (P<0.04), and a trend toward lower histologically assessed synovitis (P=0.077) compared with the low-pain intensity group. Perioperative synovitis scores were inversely correlated with pain intensity 12 months after TKA (P<0.05), indicating that more severe perioperative synovitis is associated with less severe pain intensity at 12 months.

Higher degrees of perioperative synovitis scores are found to be associated with less postoperative pain 12 months after TKA. Further, correlation analysis revealed that less severe perioperative CE-MRI and DCE-MRI synovitis was associated with higher pain intensity 12 months after TKA, suggesting that CE-MRI and DCE-MRI synovitis grades could be used as imaging markers for prediction of chronic postoperative pain after TKA.

Consultation prevalence among children, adolescents and young adults with pain conditions: A description of age- And gender differences.

Eur J Pain

Pain is a common complaint presented in healthcare, but most epidemiological pain research has focused either on single pain conditions or on the adult population. The aim of this study was to investigate the 2017 consultation prevalence of a wide range of pain conditions in the general population of young people.

We used the Skåne Healthcare Register, covering prospectively collected data on all healthcare delivered (primary and secondary care) to the population in the region of Skåne, southern Sweden (population 2017 n = 1,344,689). For individuals aged 1-24 in 2017 (n = 373,178), we calculated the consultation prevalence, stratified by sex and age, and the standardised morbidity ratio (SMR) to assess overall healthcare consultation.

A total of 58,981 (15.8%) individuals consulted at least once for any of the predefined pain conditions. Of these, 13.5% (n = 7,996) consulted four or more times for pain. Abdominal pain, joint pain/myalgia, headache and back/neck pain were the most common complaints. Overall, females had higher consultation prevalence than males: 17.6% versus 14.1% (p < .0001). SMR was 1.82 (95% CI = 1.74-1.87) for females with pain and 1.51 (95% CI = 1.42-1.56) for males with pain. Consultation prevalence increased with age, but this pattern varied between sex and pain condition.

Among individuals under the age of 25, a significant proportion consult for pain already in early ages, and they also have high healthcare consultation rates for conditions other than pain. The even higher consultation rates among young females need additional attention, both in the clinic and in research.

Impact of high spinal anesthesia technique on fast-track strategy in cardiac surgery: retrospective study.

Regional Anesthesia and Pain Medicine

Although high spinal anesthesia (HSA) has been used in cardiac surgery, the technique has not yet been widely accepted. This retrospective study was designed to investigate the impact of HSA technique on fast-track strategy in cardiac surgery.

Elective cardiac surgery cases (n=1025) were divided into two groups: cases with HSA combined with general anesthesia (GA) (HSA group, n=188) and cases with GA only (GA group, n=837). In the HSA group, bupivacaine and morphine were intrathecally administered immediately before GA was induced. Outcomes included fast-track extubation (less than 6 hours), extubation in the operating room, fast-track discharge from the intensive care unit (ICU) (less than 48 hours) and hospital (less than 7 days).

In the HSA group, 60.1% were extubated in less than 6 hours after ICU admission, as compared with 39.9% in the GA group (p<0.001). In the HSA group, 33.0% were extubated in the operating room, as compared with 4.4% in the GA group (p<0.001). LOS in the ICU was less than 48 hours in 67.6% in the HSA group, as compared with 57.2% of those in the GA group (p=0.033). LOS in the hospital was less than 7 days in 63.3% in the HSA group, as compared with 53.5% in the GA group (p=0.084).

HSA technique combined with GA in cardiac surgery increased the rate of fast-track extubation (less than 6 hours) when compared with GA only.

Sonic hedgehog signaling pathway promotes pancreatic cancer pain via nerve growth factor.

Regional Anesthesia and Pain Medicine

Many patients with pancreatic cancer (PC) suffer from abdominal pain and back pain. However, the cause of pain associated with PC is largely unclear. In this study, we tested the potential influence of the sonic hedgehog (sHH) signaling pathway on PC pain.

Substance P (SP) and calcitonin gene-related peptide (CGRP) expression was measured in cultured PC cells and dorsal root ganglions (DRG) by real-time PCR, western blotting analysis and ELISA. Small interfering RNA transfection and plasmid constructs were used to regulate the expression of sHH in the AsPc-1 and Panc-1 cell lines. Pain-related behavior was observed in an orthotopic tumor model in nude mice.

In this study, the results show that sHH increased the expression of SP and CGRP in DRGs in a concentration and time-dependent manner. Additionally, sHH secretion from PC cells could activate the sHH signaling pathway and, in turn, increase the expression of nerve growth factor (NGF), P75, and TrkA in DRGs. Furthermore, the sHH signaling pathway and NGF/NGF receptor contributed to pain sensitivity in a nude mouse model.

Our results demonstrate that PC pain originates from the sHH signaling pathway, and NGF mediates the pain mechanism via regulating SP and CGRP.

Differences in Antinociceptive Signaling Mechanisms Following Morphine and Fentanyl Microinjections into the Rat Periaqueductal Gray.

Eur J Pain

Morphine and fentanyl are two of the most commonly used opioids to treat pain. Although both opioids produce antinociception by binding to mu-opioid receptors (MOR), they appear to act via distinct signaling pathways.

This study will reveal whether differences in morphine and fentanyl antinociception are the result of selective activation of G-protein signaling and/or selective activation of pre- or postsynaptic MORs.

The contribution of each mechanism to morphine and fentanyl antinociception was assessed by microinjecting drugs to alter G-protein signaling or block potassium channels linked to pre- and post-synaptic MORs in the ventrolateral periaqueductal gray (PAG) of male Sprague-Dawley rats.

Both morphine and fentanyl produced a dose dependent antinociception when microinjected into the PAG. Enhancement of intracellular G-protein signaling by microinjection of the Regulator of G-protein Signaling 4 (RGS4) antagonist CCG-63802 into the PAG enhanced the antinociceptive potency of morphine, but not fentanyl. Microinjection of α-dendrotoxin into the PAG to block MOR activation of presynaptic Kv+ channels caused a significant rightward shift in the dose-response curve of both morphine and fentanyl. Microinjection of tertiapin-Q to block MOR activation of post-synaptic GIRK channels caused a larger shift in the dose-response curve for fentanyl than morphine antinociception.

These findings reveal different PAG signaling mechanisms for morphine and fentanyl antinociception. In contrast to fentanyl, the antinociceptive effects of morphine are mediated by G-protein signaling primarily activated by presynaptic MORs.