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
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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The nocebo effect consists in delivering verbal suggestions of negative outcomes so that the subject expects clinical worsening. Here we show that nocebo suggestions, in which expectation of pain increase is induced, are capable of producing both hyperalgesic and allodynic responses. By extending previous findings on the placebo effect, we investigated the role of learning in the nocebo effect by means of a conditioning procedure. ⋯ Therefore, in contrast to placebo analgesia, whereby a conditioning procedure elicits larger effects compared to verbal suggestions alone, learning seems to be less important in nocebo hyperalgesia. Overall, these findings indicate that, by defining hyperalgesia as an increase in pain sensitivity and allodynia as the perception of pain in response to innocuous stimulation, nocebos can indeed produce both hyperalgesic and allodynic effects. These results also suggest that learning is not important in nocebo hyperalgesia compared to placebo analgesia.
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Comparative Study
A pain assessment scale for population-based studies: development and validation of the pain module of the Standard Evaluation Questionnaire.
The objectives of this study were to develop and validate a tool for assessing pain in population-based observational studies and to develop three subscales for back/neck, upper extremity and lower extremity pain. Based on a literature review, items were extracted from validated questionnaires and reviewed by an expert panel. The initial questionnaire consisted of a pain manikin and 34 items relating to (i) intensity of pain in different body regions (7 items), (ii) pain during activities of daily living (18 items) and (iii) various pain modalities (9 items). ⋯ Correlation coefficients between subscales and three validated instruments (WOMAC, SPADI and Oswestry) ranged from 0.62 to 0.79. The final Pain Standard Evaluation Questionnaire (SEQ Pain) included 28 items and the pain manikin and accounted for the multidimensionality of pain by assessing pain location and intensity, pain during activity, triggers and time of onset of pain and frequency of pain medication. It was found to be reliable and valid for the assessment of pain in population-based observational studies.
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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.