Pain
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Intraspinal injections of the AMPA-metabotropic receptor agonist quisqualic acid (QUIS) were made in an effort to simulate injury induced elevations of excitatory amino acids (EAAs), a well documented neurochemical change following spinal cord injury (SCI). The progressive pathological sequela associated with QUIS injections closely resembles the cascade of events described following ischemic and traumatic SCI and the pathogenesis of cavities in the clinical condition of post-traumatic syringomyelia. ⋯ Thus, the present results provide a morphological correlate of spontaneous and evoked pain related behaviors following excitotoxic SCI. The behavioral characteristics combined with the similarities between QUIS induced injury and the clinical pathology of SCI support the use of the excitotoxic model in studies related to the central mechanism(s) of altered sensation, including pain, following spinal injury.
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Gender differences in experimental pain sensitivity have been widely investigated, and the results generally indicate that females exhibit greater sensitivity to noxious stimuli than males. However, results using thermal pain procedures have been inconsistent, with some studies reporting greater responses among females and other studies reporting no gender differences. ⋯ The results indicated lower thermal pain threshold and tolerance and greater temporal summation of thermal pain among females, but no gender differences in thermal discrimination or real-time magnitude estimates of discrete heat pulses. These findings suggest that gender differences in thermal pain perception may be more robust for sustained, temporally dynamic thermal stimuli with a strong C-fiber component.
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The objective of this study was to assess outcomes of pediatric day surgery tonsillectomy. A total of 129 children, aged 5-16 years, and their parents were recruited from three urban hospitals which provided pediatric day surgery. Children reported pain on a visual analogue scale (VAS) in day surgery and then daily at home for 7 days. ⋯ The increase in postoperative pain experienced by those who had the infiltration was attributed to quality of pain management. Children with persistent pain (those who did not follow the typical trajectory) were likely to be taken to a medical practitioner. One-third of the sample made unscheduled visits to practitioners with most occurring from Day 4 to Day 7 of the follow-up.
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Nociceptive electrical stimuli were applied to the sural nerve during hypnotically-suggested analgesia in the left lower limb of 18 highly susceptible subjects. During this procedure, the verbally reported pain threshold, the nociceptive flexion (RIII) reflex and late somatosensory evoked potentials were investigated in parallel with autonomic responses and the spontaneous electroencephalogram (EEG). The hypnotic suggestion of analgesia induced a significant increase in pain threshold in all the selected subjects. ⋯ No modification in the autonomic parameters or the EEG was observed. These data suggest that different strategies of modulation can be operative during effective hypnotic analgesia and that these are subject-dependent. Although all subjects may shift their attention away from the painful stimulus (which could explain the decrease of the late somatosensory evoked potentials), some of them inhibit their motor reaction to the stimulus at the spinal level, while in others, in contrast, this reaction is facilitated.
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The psychological assessment of chronic pain is often accomplished using questionnaires such as the (West Haven-Yale) Multidimensional Pain Inventory ((WHY)MPI) which is constructed to capture the multidimensionality of chronic pain. The (WHY)MPI theoretically originates from behavioural and cognitive behavioural theories of pain. It is divided into three parts and measures psychosocial and behavioural consequences of pain. ⋯ This part of the inventory is designed to measure the extent of different types of activities, and our results suggest that this section may only be used for assessing general activity level. We conclude that, with a few adjustments, the analyses yielded satisfactory results for sections 1 and 2 of the MPI-S regarding its factor structure, reliability and generalisability. For section 3 the hypothesised factor structure could not be confirmed.