Articles: hyperalgesia.
-
Randomized Controlled Trial
The initial effects of knee joint mobilization on osteoarthritic hyperalgesia.
Physiotherapists often employ lower limb joint mobilization to reduce pain and increase function. However, there is little experimental data confirming its efficacy. The purpose of this study was to investigate the initial effects of accessory knee joint mobilization on measures of pain and function in individuals with knee osteoarthritis. ⋯ Knee joint mobilization also increased PPT at a distal, non-painful site and reduced 'up and go' time significantly more (-5% (-9.3 to 0.8)) than manual contact (-0.4% (-4.2 to 3.5)) or no-contact control (+7.9% (2.6-13.2)) interventions. This study therefore provides new experimental evidence that accessory mobilization of an osteoarthritic knee joint immediately produces both local and widespread hypoalgesic effects. It may therefore be an effective means of reducing pain in this population.
-
Randomized Controlled Trial
Thermal and visceral hypersensitivity in irritable bowel syndrome patients with and without fibromyalgia.
Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by both visceral and somatic hyperalgesia, producing a similar effect seen with the central hypersensitivity mechanism in fibromyalgia (FM). ⋯ FM+IBS patients show greater thermal hypersensitivity compared with IBS patients. However, IBS patients exhibit higher pain ratings to rectal distension compared with FM+IBS patients. This data suggests that regions of primary and secondary hyperalgesia are dependent on the primary pain complaint.
-
Comparative Study
ASIC3 in muscle mediates mechanical, but not heat, hyperalgesia associated with muscle inflammation.
Peripheral initiators of muscle pain are virtually unknown, but likely key to development of chronic pain after muscle insult. The current study tested the hypothesis that ASIC3 in muscle is necessary for development of cutaneous mechanical, but not heat, hyperalgesia induced by muscle inflammation. Using mechanical and heat stimuli, we assessed behavioral responses in ASIC3-/- and ASIC3+/+ mice after induction of carrageenan muscle inflammation. ⋯ Injection of ASIC3-encoding virus into muscle or skin of ASIC3-/- mice resulted in ASIC3 mRNA in DRG and protein expression in DRG and the peripheral injection site. Injection of ASIC3-encoding virus into muscle, but not skin, resulted in development of mechanical hyperalgesia similar to that observed in ASIC3+/+ mice. Thus, ASIC3 in primary afferent fibers innervating muscle is critical to development of hyperalgesia that results from muscle insult.
-
Reg Anesth Pain Med · May 2007
Chronic intrathecal infusion of minocycline prevents the development of spinal-nerve ligation-induced pain in rats.
Minocycline is a second-generation tetracycline with multiple biological effects, including inhibition of microglial activation. Recently, microglial activation has been implicated in the development of nerve injury-induced neuropathic pain. In this study, the authors examined the effects of continuous intrathecal minocycline on the development of neuropathic pain and microglial activation induced by L5/6 spinal-nerve ligation in rats. ⋯ In this study, the authors demonstrate the preventive effect of continuous intrathecal minocycline on the development of nociceptive behaviors induced by L5/6 spinal-nerve ligation in rats. Further studies are required to examine if continuous intrathecal minocycline could be used safely in the clinical setting.
-
J. Pharm. Pharmacol. · May 2007
Differential involvement of TRPV1 receptors at the central and peripheral nerves in CFA-induced mechanical and thermal hyperalgesia.
Transient receptor potential vanilloid 1 (TRPV1) antagonists are known to attenuate two typical symptoms of inflammatory hyperalgesia: thermal and mechanical. However, it is not clear whether the sites of participation of TRPV1 for each symptom are different. In this study, we clarified the difference between the site of TRPV1 involvement in both symptoms by analysing the anti-hyperalgesic activity of two kinds of TRPV1 antagonists given locally (i.e. intraplantarly and intrathecally) in rats with CFA (complete Freund's adjuvant)-induced inflammation. ⋯ Regression analysis showed that a correlation exists between the inhibitory effects on thermal hyperalgesia and mechanical hyperalgesia after intrathecal administration (correlation factor = 0.6521), but not after intraplantar administration (correlation factor = 0.0215). These data suggest that TRPV1 in the peripheral endings of the primary afferents plays a key role in thermal hyperalgesia, but it makes only a minor contribution in CFA-induced mechanical hyperalgesia. Furthermore, it is suggested that the spinal TRPV1 is critical in the development of both types of hyperalgesia.