Pain
-
The rostral ventromedial medulla (RVM) is involved in facilitation of spinal nociceptive processing and generation of hyperalgesia in inflammatory and neuropathic pain models. We hypothesized that the bilateral hyperalgesia that develops after repeated intramuscular injections of acidic saline is initiated and maintained by activation of descending facilitatory pathways from the RVM. Male Sprague-Dawley rats were implanted with intracerebral guide cannulae into the nucleus raphe magnus (NRM) or the nucleus gigantocellularis (Gi). ⋯ However, neither cutaneous nor muscle hyperalgesia developed in the group treated with ropivacaine prior to the second intramuscular injection. Ropivacaine also significantly reversed the hyperalgesia in the group treated 24h after the second intramuscular acid injection. Thus, the RVM is critical for both the development and maintenance of hyperalgesia after muscle insult.
-
Prior research suggests emotional picture-viewing modulates motoric (nociceptive flexion reflex), autonomic (skin conductance response, heart rate acceleration), and subjective (pain rating) reactions to noxious electrodermal stimulation. The present study sought to determine whether emotional valence and arousal contribute to nociception modulation. To do so, pictures varying in emotional content (erotica, food, neutral, loss, attack) were chosen to manipulate emotional valence (pleasant=erotic and food; unpleasant=loss and attack) and arousal (low=food and loss; moderate=erotica and attack). ⋯ An exploratory multilevel analysis also supported this conclusion. Together, these data suggest emotional control of nociceptive reactions (ECON) is associated with a valence-by-arousal interaction. Implications of these findings for how emotional picture-viewing can be used to study supraspinal modulation are discussed.
-
This study examined arthritis self-efficacy and self-efficacy for resisting eating as predictors of pain, disability, and eating behaviors in overweight or obese patients with osteoarthritis (OA) of the knee. Patients (N=174) with a body mass index between 25 and 42 completed measures of arthritis-related self-efficacy, weight-related self-efficacy, pain, physical disability, psychological disability, overeating, and demographic and medical information. Hierarchical linear regression analyses were conducted to examine whether arthritis self-efficacy (efficacy for pain control, physical function, and other symptoms) and self-efficacy for resisting eating accounted for significant variance in pain, disability, and eating behaviors after controlling for demographic and medical characteristics. ⋯ Findings indicate that self-efficacy is important in understanding pain and behavioral adjustment in overweight or obese OA patients. Moreover, the contributions of self-efficacy were domain specific. Interventions targeting both arthritis self-efficacy and self-efficacy for resisting eating may be helpful in this population.
-
We conducted a large nationwide postal survey to estimate the prevalence of chronic pain with or without neuropathic characteristics in the French general population. A questionnaire aimed at identifying chronic pain (defined as daily pain for at least 3 months), evaluating its intensity, duration and body locations, was sent to a representative sample of 30,155 subjects. The DN4 questionnaire was used to identify neuropathic characteristics. ⋯ It was more frequently located in the lower limbs and its intensity and duration were higher in comparison with chronic pain without neuropathic characteristics. This large national population-based study indicates that a significant proportion of chronic pain patients report neuropathic characteristics. We identified distinctive socio-demographic profile and clinical features indicating that chronic pain with neuropathic characteristics is a specific health problem.
-
The objective of this study was to investigate associations between social desirability response bias and self-report of pain, disability, and psychological distress (depression, anxiety, and somatic symptoms) in a sample of children presenting to a multidisciplinary pediatric chronic pain clinic. A retrospective review was conducted on 414 consecutive clinic patients, ages 12-17 years, with chronic pain complaints of at least 3 months' duration. As part of a clinical battery, children completed self-report psychological questionnaires including the Children's Depression Inventory, Children's Somatization Inventory, and Revised Children's Manifest Anxiety Scale including the Lie Scale, an indicator of social desirability influence. ⋯ No differences arose between these groups on reports of somatic symptoms, pain duration, or pain-related disability. These findings suggest that social desirability response bias may have implications for the self-report of psychological distress among pediatric chronic pain patients. The limits of self-report of symptoms should be considered in the clinical and research contexts.