Pain
-
Clinical Trial
Temporo-spatial analysis of cortical activation by phasic innocuous and noxious cold stimuli--a magnetoencephalographic study.
Clinical findings and recent non-invasive functional imaging studies pinpoint the insular cortex as the crucial brain area involved in cold sensation. By contrast, the role of primary (SI) and secondary (SII) somatosensory cortices in central processing of cold is controversial. So far, temporal activation patterns of cortical areas involved in cold processing have not been examined. ⋯ In conclusion, this study strongly corroborates the posterior insular cortex as the primary somatosensory area for cortical processing of cold sensation. Furthermore, it supports the role of SII and the cingulate cortex in mediating freeze-pain. Therefore, these results suggest different processing of cold, freeze-pain and touch in the human brain.
-
Spinal antinociception produced by delta 9-tetrahydro-cannabinol (Delta(9)-THC) and other cannabinoid agonists has been suggested to be mediated by the release of dynorphin acting at the kappa opioid receptor. Alternatively, as cannabinoid receptors are distributed appropriately in the pain transmission pathway, cannabinoid agonists might act directly at the spinal level to inhibit nociception, without requiring dynorphin release. Here, these possibilities were explored using mice with a deletion of the gene encoding prodynorphin. ⋯ However, the same dose of nor-BNI used blocked U50,488H-induced antinociception in both wild-type and prodynorphin knock-out mice, confirming kappa opioid receptor activity. Pretreatment with SR141716A, a cannabinoid receptor antagonist blocked the antinociceptive actions of both WIN 55,212-2 and Delta(9)-THC. These data support the conclusion that antinociception produced by spinal cannabinoids are likely to be mediated directly through activation of cannabinoid receptors without the requirement for dynorphin release or activation of kappa opioid receptors.
-
The purpose of this study was to examine racial/ethnic-related differences in a four-stage model of the processing of chronic pain. The subjects were 1557 chronic pain patients (White=1084, African American=473) evaluated at a pain management clinic at a large southeastern university medical center. Using an analysis of covariance controlling for pain duration and education, African American patients reported significantly higher levels of pain unpleasantness, emotional response to pain, and pain behavior, but not pain intensity than Whites. ⋯ The groups differed by approximately 1.0 visual analogue scale unit, a magnitude that may be clinically significant. Racial/ethnic differences in the linear relationship between stages were also tested using structural equation modeling and LISREL-8. The results indicate differences in linear associations between pain measures with African Americans showing a stronger link between emotions and pain behavior than Whites.
-
This case presents a patient with neuropathic pain in a lower extremity, which appeared subsequent to the removal of a C1 meningioma and which was successfully treated by lower thoracic spinal cord stimulation.