The journal of pain : official journal of the American Pain Society
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Variable use of pain scale anchors may influence recalled pain ratings, rating consistency, and agreement between actual rating change and ratings of pain relief. This investigation examined change in events that represent maximal pain scale anchors. Participants (N = 68, 50% women) provided events for maximal anchors of 0 to 100 pain scales, and cold pressor pain was rated by using self-selected event/s and an investigator-provided event. Participants then were allowed to change their self-selected event/s. The revised event/s or original events were then used to rate a second cold pressor trial. Forty-one percent of participants changed event/s, and the new event/s was more likely to involve cold or heat, but the painfulness of events and the pain ratings of the second trial did not change. The cold pressor pain ratings were higher when rated on the basis of self-selected event/s than the investigator-provided event for intensity (mean = 80.13, SD = 19.30; mean = 60.81, SD = 27.45) and unpleasantness (mean = 80.84, SD = 19.07; mean = 59.07, SD = 27.53), which could be due to the submaximal painfulness of the investigator-provided event. Therefore, the width of numerical scales is stable with maximal events regardless of the actual events. ⋯ This report identifies change in physical events that are used by participants to represent maximal pain scale anchors and suggests that the maximal nature of the events' painfulness is more important than variability in the actual events. We conclude that the numerical pain scales we used are understandable and stable, but we suggest that instructional sets for pain measurement may be improved by evaluation of the painfulness of events that respondents use to conceptualize maximal pain scale anchors.
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Characteristics of sensory dorsal root ganglia (DRG) neurons innervating the L5 vertebral body were investigated in rats by using a retrograde neurotransport method, lectin affinity- and immuno-histochemistry to further elucidate the causes of diffuse pain suffered by some elderly patients in their back, lateral trunk, and iliac crest, after lumbar osteoporotic vertebral fracture. We used calcitonin gene-related peptide (CGRP) as a marker of small peptide-containing neurons and the glycoprotein binding the isolectin from Griffonia simplicifolia (IB4) as a marker of small non-peptide-containing neurons. Neurons innervating the L5 vertebral bodies, retrogradely labeled with fluoro-gold (FG), were distributed throughout DRGs from T13 to L6. The proportion of CGRP-immunoreactive (IR) FG-labeled neurons was 32%. The proportion of IB4-binding FG-labeled neurons was significantly smaller, at 4%. Other neurons that were non-CGRP-IR and non-IB4-binding were mostly large neurons, and they may transmit proprioception from vertebral bodies. Most neurons transmitting pain are CGRP-IR peptide-containing neurons. They may have a more significant role in pain sensation in the vertebral bodies as peptidergic DRG neurons. ⋯ This article shows that vertebral bodies are innervated by CGRP-IR neurons. CGRP-IR neurons may play a role in pain sensation through peptidergic DRG neurons. These findings contribute to an understanding of pain associated with the vertebral body such as tumor, infection, or osteoporotic fracture.
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The aim of this study was to examine whether gastric afferent information converged onto upper thoracic spinal neurons that received noxious cardiac input. Extracellular potentials of single upper thoracic (T3) spinal neurons were recorded in pentobarbital-anesthetized, paralyzed, ventilated male rats. Gastric distension (GD) (20, 40, 60 mm Hg, 20 seconds) was produced by air inflation of a latex balloon surgically placed in the stomach. A catheter was placed in the pericardial sac to administer bradykinin solution (10 microg/mL, 0.2 mL, 1 minute) as a noxious cardiac stimulus. Noxious GD (> or =40 mm Hg) altered activity of 26 of 31 (84%) spinal neurons receiving cardiac input. Twenty-two (85%) gastrocardiac convergent neurons were excited, and 1 neuron was inhibited by both intrapericardial bradykinin and GD; the remainder exhibited biphasic response patterns. Twenty-three of 26 (88%) gastrocardiac neurons also received convergent somatic input from the chest, triceps, and upper back areas. Bilateral cervical vagotomy did not significantly affect excitatory responses to GD in 5 of 5 neurons tested. Spinal transection at the C1 segment after vagotomy did not affect excitatory responses to GD in 3 of 4 neurons but abolished the GD response in 1 neuron. These data showed that a gastric stimulus excited T3 spinal neurons with noxious cardiac input primarily by way of intraspinal ascending pathways. ⋯ Convergence of gastric afferent input onto upper thoracic spinal neurons receiving noxious cardiac input that was observed in the present study may provide a spinal mechanism that explains stomach-heart cross-organ communication, such as postprandial triggering and worsening of angina pectoris in patients with coronary artery disease.
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There has been growing interest among researchers and clinicians in the role of ambivalence over emotional expression (AEE) in adjustment to chronic illness. Because of the salience of anger in chronic low back pain, this condition provides a particularly good model in which to examine the role of AEE. This study examined the relation of AEE to pain and anger in a sample of 61 patients with chronic low back pain. Patients completed standardized measures of AEE, pain, and anger. Correlational analyses showed that patients who had higher AEE scores reported higher levels of evaluative and affective pain as well as higher levels of state and trait anger and the tendency to hold in angry thoughts and feelings. Mediational analyses revealed that most of the associations between AEE and pain, and AEE and anger, were independent of one another. These findings suggest that a potentially important relationship exists between AEE and key aspects of living with persistent pain. ⋯ This preliminary study suggests that there is a relation between ambivalence over emotional expression and pain and anger in patients with chronic low back pain. Patients who report greater conflict with regard to expressing emotions may be experiencing higher pain and anger.
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Several medications are recommended for relief of postherpetic neuralgia (PHN). A sequential treatment algorithm has been suggested, but its cost-effectiveness is unclear. We developed a decision model to estimate the cost-effectiveness of this algorithm compared with other sequential medication strategies in 70-year-olds with PHN, using literature data to model medication-related PHN relief while also accounting for severe medication side effects. Hypothetical patients with and without coronary artery disease (CAD) were considered separately, with and without localized pain. Sequential medication switches occurred as the result of inadequate relief or intolerable side effects. Probabilistic sensitivity analyses were performed to estimate the favorability of each medication early in treatment sequences. In patients without CAD, tricyclic and gabapentin were equally favored as initial therapy if mortality with tricyclic use was not increased, but gabapentin was strongly favored if it was. In patients with CAD, gabapentin was overwhelmingly favored. In either patient group, opioids, pregabalin, and tramadol were not favored as initial therapy but were sensible choices later in treatment sequences. The lidocaine patch was a reasonable first choice in patients with localized PHN. Our analysis supports the suggested treatment algorithm, with cost-effectiveness ratios within acceptable ranges for medications given sequentially, based on literature-based estimates of effectiveness and tolerability. ⋯ This article examines the cost-effectiveness of recommended sequential treatment strategies for postherpetic neuralgia. This decision analysis-based synthesis of effectiveness and cost data found that recommended treatment algorithms are also economically reasonable.