Articles: hyperalgesia.
-
Anesthesia and analgesia · Sep 2016
The Antiallodynic Effects of Nefopam Are Mediated by the Adenosine Triphosphate-Sensitive Potassium Channel in a Neuropathic Pain Model.
Nefopam hydrochloride is a centrally acting compound that induces antinociceptive and antihyperalgesic properties in neuropathic pain models. Previous reports have shown that activation of adenosine triphosphate (ATP)-sensitive and calcium-activated potassium (KATP and KCa2+) channels has antiallodynic effects in neuropathic pain. In the present study, we evaluated the relationship between potassium channels and nefopam to determine whether the antiallodynic effects of nefopam are mediated by potassium channels in a neuropathic pain model. ⋯ The antiallodynic effects of nefopam are increased by a KATP channel agonist and reversed by a KATP channel antagonist. These data suggest that the KATP channel is involved in the antiallodynic effects of nefopam in a neuropathic pain model.
-
Randomized Controlled Trial
Effects of Different Anesthetics on Pain Processing in an Experimental Human Pain Model.
After surgical procedures, anesthesia itself may affect pain perception. Particularly, there is increasing evidence that opioids not only have analgesic effects but also provoke pronociceptive changes, that is, opioid-induced hyperalgesia. We investigated the effect of different anesthetic regimens on pain processing in volunteers using a transdermal electrical pain model. In this model, stimulation of epidermal nerve fibers representing mainly peptidergic C-nociceptors leads to secondary hyperalgesia and habituation to the stimulus. ⋯ The results suggest a short-term analgesic effect of general anesthesia. Furthermore, the conditioning stimulation over several days induced differential modulation of pro- and antinociceptive systems.
-
To investigate whether analgesic effect of electroacupuncture (EA) is affected by p38 mitogen-activated protein kinase (p38 MAPK) on microglia. ⋯ The central mechanism of EA-induced anti-hyperalgesia may be partially associated with the reduced expression of p-p38 MAPK, and subsequently reducing the activation of OX-42 in neuropathic pain. Therefore, EA may be a new complementary and alternative therapy for neuropathic pain.
-
The aim of the study was to investigate clinical features of headache associated with minor versus moderate to severe traumatic brain injury and of posttraumatic versus primary headache in children and adolescents. Study group included 74 patients after mild (n = 60) or moderate to severe (n = 14) traumatic brain injury identified by retrospective review of the computerized files of a tertiary pediatric headache clinic. Forty patients (54%) had migraine-like headache, 23 (31.1%) tension-like headache, and 11 (14.9%) nonspecified headache. ⋯ In comparison with 174 control patients, the study group had a significantly lower proportion of patients with migraine-like headache and a higher proportion of male patients and patients with allodynia. There was no statistically significant correlation of any of the clinical parameters with the type or severity of the posttraumatic headache or rate of allodynia. The high rate of allodynia in the study group may indicate a central sensitization in posttraumatic headache.
-
Injection of the noxious peptide Bv8 has previously been shown to induce a biphasic thermal hyperalgesia in rodents, the first peak presumably due to peripheral sensitization. This hypothesis has never been directly confirmed. We have assessed whether Bv8 can indeed sensitize peripheral nerve fibres in the mouse to heat. ⋯ Our results thus support the hypothesis that the first hyperalgesic phase to follow Bv8 injection to hind paws of intact animals is due to peripheral sensitization of nociceptors. WHAT DOES THIS STUDY ADD?: Our data provide mechanistic insights into the effect Bv8 application exerts on afferent nerve endings and into the concomitant development of thermal hyperalgesia.