Articles: hyperalgesia.
-
Neuropathic pain results from lesions or diseases affecting the somatosensory system. The management of patients with chronic neuropathic pain remains a challenge. Several studies support the crucial role of neuroactive steroids in the modulation of pain. ⋯ The chronic administration of progesterone significantly reduced the behavioral scores of cold- and mechano-allodynia and heat hyperalgesia but single dose of progesterone did not have any effect on behavioral scores of neuropathic pain. Our data indicate that the early chronic administration of progesterone prevents the development of neuropathic pain but its acute injection does not change the expression of neuropathic pain. These results suggest that progesterone could be considered as a new approach for management of neuropathic pain.
-
Inflammation is a major factor shaping outcome during the early, acute phase of traumatic spinal cord injury (SCI). It is known that pro-inflammatory signaling within the injured spinal cord drives pathological alterations in neurosensory processing and shapes functional outcome early after injury. However, it is unclear whether inflammation persists into the chronic phase of injury or shapes sensory processing long after injury. ⋯ We found that 28 d treatment of chronically injured rats with the dual COX/5-LOX inhibitor licofelone elevated levels of endogenous anti-oxidant and anti-inflammatory metabolites within the lesion site. Furthermore, licofelone treatment reduced hypersensitivity of hindpaws to mechanical, but not thermal, stimulation, indicating that mechanical sensitivity is modulated by pro-inflammatory signaling in the chronic phase of injury. Together, these findings provide novel evidence of inflammation and oxidative stress within spinal cord tissue far into the chronic phase of SCI, and demonstrate a role for inflammatory modulation of mechanical sensitivity in the chronic phase of injury.
-
Randomized Controlled Trial
Amygdala activity contributes to the dissociative effect of cannabis on pain perception.
Cannabis is reported to be remarkably effective for the relief of otherwise intractable pain. However, the bases for pain relief afforded by this psychotropic agent are debatable. Nonetheless, the frontal-limbic distribution of cannabinoid receptors in the brain suggests that cannabis may target preferentially the affective qualities of pain. ⋯ Critically, the reduction in sensory-limbic functional connectivity was positively correlated with the difference in drug effects on the unpleasantness and the intensity of ongoing pain. Peripheral mechanisms alone cannot account for the dissociative effects of THC on the pain that was observed. Instead, the data reveal that amygdala activity contributes to interindividual response to cannabinoid analgesia, and suggest that dissociative effects of THC in the brain are relevant to pain relief in humans.
-
Anesthesia and analgesia · Jan 2013
Persistent hyperalgesia in the cisplatin-treated mouse as defined by threshold measures, the conditioned place preference paradigm, and changes in dorsal root ganglia activated transcription factor 3: the effects of gabapentin, ketorolac, and etanercept.
Painful neuropathy is a dose-limiting side effect in cancer chemotherapy. To characterize this phenomenon, we examined pain behavior and analgesic actions in a mouse model of cisplatin polyneuropathy. ⋯ Cisplatintreated mice display allodynia and an activation of DRG activated transcription factor 3, which is paralleled by its effects on behavior in the CPP system, wherein gabapentin, but not ketorolac, in the presence of the cisplatin polyneuropathy, is positively rewarding, confirming that this neuropathy is an aversive (painful) state that is ameliorated by gabapentin.
-
Randomized Controlled Trial Comparative Study
Remifentanil-induced tolerance, withdrawal or hyperalgesia in infants: a randomized controlled trial. RAPIP trial: remifentanil-based analgesia and sedation of paediatric intensive care patients.
Short-acting opioids like remifentanil are suspected of an increased risk for tolerance, withdrawal and opioid-induced hyperalgesia (OIH). These potential adverse effects have never been investigated in neonates. ⋯ Remifentanil does not seem to be associated with an increased risk for tolerance, withdrawal or OIH.