Pain
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Chronic pain interrupts behaviour, interferes with functioning, and may affect a person's identity: their sense of self. We tested whether loss of role and personal attributes and current and past self-concept differentiation, predicted adjustment as indexed by measures of depression. Chronic pain patients (n=80) completed measures of pain (MPQ), disability (PDI), depression and anxiety (BDI, HADS). ⋯ Multiple regression analyses revealed that after controlling for demographic and clinical differences, role and attribute loss predicted depression scores. There was no evidence that depression was associated with past self-concept differentiation. The results are discussed with reference to the methodology used and the relevance of self-identity to understand adjustment to chronic pain.
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Reduced habituation to experimental pain in migraine patients: a CO(2) laser evoked potential study.
The habituation to sensory stimuli of different modalities is reduced in migraine patients. However, the habituation to pain has never been evaluated. Our aim was to assess the nociceptive pathway function and the habituation to experimental pain in patients with migraine. ⋯ Moreover, while the N1-P1 amplitude showed a significant habituation in CS after hand stimulation, it did not change across repetitions in MO patients. In conclusion, no functional impairment of the nociceptive pathways, including the trigeminal pathways, was found in either MO or CTTH patients. But patients with migraine had a reduced habituation, which probably reflects an abnormal excitability of the cortical areas involved in pain processing.
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In male rats, carrageenan (CAR)-induced inflammation or exposure to a selective protein kinase C epsilon (PKC epsilon ) agonist (psi epsilon RACK) produces prolongation of the hyperalgesia induced by a subsequent exposure to an inflammatory mediator, a phenomenon referred to as hyperalgesic priming. Since many chronic inflammatory conditions are sexually dimorphic, we tested the hypothesis that hyperalgesic priming is sexually dimorphic. Prior injection of CAR or psi epsilon RACK produced a prolongation of the hyperalgesia induced by a subsequent injection of prostaglandin E(2), from less than 3 h to greater than 24 h, but only in male rats. ⋯ While gonadectomy in males had no effect on CAR and psi epsilon RACK induced hyperalgesic priming, female phenotype was observed following implantation of estrogen in males. Thus, mechanisms mediating the development of hyperalgesic priming produced by inflammation are suppressed by estrogen. This regulation of priming by estrogen appears to occur at or downstream of the activation of PKC epsilon.
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Irritable bowel syndrome (IBS) is one of the most common gastrointestinal illnesses and is characterized by altered visceral perception. The aim of the study was to determine if local anesthetic blockade of peripheral visceral nociceptive input reduces both visceral and cutaneous secondary hyperalgesia in IBS patients. Ten women with IBS (mean age 30+/-10 years) and ten control subjects (all women) (mean age 29+/-7 years) rated pain intensity and unpleasantness to distension of the rectum (35 mmHg) and thermal stimulation (47 degrees C) of the foot before and after rectal administration of either lidocaine jelly or saline jelly in a double blind crossover design. ⋯ The results of this study support the hypothesis that local anesthetic blockade of peripheral impulse input from the rectum/colon reduces both visceral and cutaneous secondary hyperalgesia in IBS patients. The results provide further evidence that visceral hyperalgesia and secondary cutaneous hyperalgesia in IBS reflects central sensitization mechanisms that are dynamically maintained by tonic impulse input from the rectum/colon. Rectal administration of lidocaine jelly may also be a safe and effective means of reducing pain symptoms in IBS patients.
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Fear of movement/(re)injury and its associated avoidance behavior have shown to be strongly associated with functional disability in chronic low back pain. In acute low back pain disability, the role of pain-related fear has received little research attention so far. Measures of pain-related fear such as the Tampa Scale for Kinesiophobia (TSK) are increasingly being used in primary care. ⋯ Additionally, and in contrast to what is often observed in chronic pain, disability, and to a lesser degree participation, were also associated with pain intensity. Finally, the association between pain-related fear, pain intensity and participation was indeed mediated by disability. The results suggest that early on in the development of LBP disability, the successful reduction of pain-related fear and disability might foster increased participation in daily and social life activities.