Pain
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Comparative Study
Illness perceptions of low back pain patients in primary care: what are they, do they change and are they associated with outcome?
We describe the illness perceptions of patients with low back pain, how they change over 6 months, and their associations with clinical outcome. Consecutive patients consulting eight general practices were eligible to take part in a prospective cohort study, providing data within 3 weeks of consultation and 6 months later. Illness perceptions were measured using the Revised Illness Perception Questionnaire (IPQ-R). ⋯ There were strong, statistically significant, associations (RRs of 1.4 and over) between IPQ-R baseline consequences, timeline acute/chronic, personal control and treatment control scores and poor outcome. Patients who expected their back problem to last a long time, who perceived serious consequences, and who held weak beliefs in the controllability of their back problem were more likely to have poor clinical outcomes 6 months after they consulted their doctor. These results have implications for the management of patients, and support the need to assess and address patients' cognitions about their back problems.
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Comparative Study
Evidence for a biopsychosocial influence on shoulder pain: pain catastrophizing and catechol-O-methyltransferase (COMT) diplotype predict clinical pain ratings.
The experience of pain is believed to be influenced by social, cultural, environmental, psychological, and genetic factors. Despite this assertion, few studies have included clinically relevant pain phenotypes when investigating interactions among these variables. This study investigated whether psychological variables specific to fear-avoidance models and catechol-O-methyltransferase (COMT) genotype influenced pain ratings for a cohort of patients receiving operative treatment of shoulder pain. ⋯ A hierarchical regression model indicated that an interaction between pain catastrophizing and COMT diplotype contributed additional variance in pre-operative pain ratings. The pain catastrophizingxCOMT diplotype interaction demonstrated predictive validity as patients with high pain catastrophizing and low COMT activity (APS/HPS group) were more likely (RR=6.8, 95% CI=2.8-16.7) to have post-operative pain ratings of 4.0/10 or higher. Our findings suggest that an interaction between pain catastrophizing and COMT diplotype has the potential to influence pain ratings in patients seeking operative treatment of their shoulder pain.
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Randomized Controlled Trial Comparative Study
Pregabalin in patients with central neuropathic pain: a randomized, double-blind, placebo-controlled trial of a flexible-dose regimen.
The effective treatment of patients suffering from central neuropathic pain remains a clinical challenge, despite a standard pharmacological approach in combination with anticonvulsants and antidepressants. A randomized, double-blinded, placebo-controlled trial evaluated the effects of pregabalin on pain relief, tolerability, health status, and quality of life in patients with central neuropathic pain caused by brain or spinal cord injuries. At baseline and 4 weeks after the start of treatment subjects were evaluated with standard measures of efficacy: pain intensity measured by visual analog scale, health status (Pain Disability Index and EQ-5D) and quality of life (SF-36). ⋯ Pregabalin treatment led to a significant improvement in the bodily pain domain of the SF36. In the other domains, more favorable scores were reported without reaching statistical significance. Pregabalin, in a flexible-dose regime, produced clinically significant reductions in pain, as well as improvements in health status in patients suffering from severe central neuropathic pain.
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Comparative Study
Effects of stress on pain threshold and tolerance in children with recurrent abdominal pain.
Models of stress-induced hyperalgesia state that exposure to stress can exaggerate subsequent pain experiences. Studies using both animal and human subjects have shown evidence for hyperalgesia as a function of stress [e.g., Jorum E. Analgesia or hyperalgesia following stress correlates with emotional behavior in rats. ⋯ Children who underwent the stress tasks before the pain task exhibited lower levels of pain tolerance than those who received the pain task first (p<.01); no differences were found between the two groups in pain threshold or pain intensity ratings. Further, pain tolerance was not related to individual differences in physiological reactivity (heart rate change) to the stressor. The present research demonstrates the first evidence of the occurrence of stress-induced hyperalgesia in a pediatric pain population.
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Comparative Study
Empathy hurts: compassion for another increases both sensory and affective components of pain perception.
Recent studies demonstrate that some brain structures activated by pain are also engaged when an individual observes someone else in pain, and that these empathy-related responses are modulated as a function of the affective link between the empath and the individual in pain. In this study we test the hypothesis that empathy-evoked activation in the pain network leads to heightened pain perception. ⋯ Positive correlations between state empathy scores and pain ratings further suggest that this perceptual phenomenon depends on the magnitude of empathic response induced in the participants. The effects were observed when subjects watched the model receiving either neutral or painful stimuli, suggesting that it is empathy itself that alters pain perception, and not necessarily the observation of pain behaviors.