Articles: hyperalgesia.
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Crohn's disease (CD) is a painful chronic inflammatory bowel disease. It primarily affects terminal ileum, but the involvement of large and small intestines or extraintestinal manifestations is very common. CD may go along with neurogenic inflammation, mediated by substance P and CGRP, which are also key players in pain transmission. This may in turn contribute to hyperalgesia and altered somatosensory function in CD. ⋯ Our findings are consistent with the presence of a subclinical small fiber neuropathy. The group of CD patients with pronounced neuropathy findings were predominantly males, had a higher incidence of extraintestinal manifestations, and tended to have a longer history of disease duration.
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Transcutaneous electrical nerve stimulation (TENS) is a non-invasive analgesic resource extensively used in painful conditions. However, preclinical studies suggest that the prolonged use of TENS results in the development of tolerance to its analgesic effect. The present study investigated the analgesic effect and development of tolerance to TENS with four different stimulation protocols. ⋯ The association between frequency variation and intensity at motor level promotes a delay in the development of analgesic tolerance to TENS, optimizing and extending its therapeutic effectiveness.
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J Pain Symptom Manage · Mar 2015
Opioid-induced hyperalgesia (OIH): a real clinical problem or just an experimental phenomenon?
Although opioid-induced hyperalgesia (OIH) is mentioned as a potential cause of opioid dose escalation without adequate analgesia, true evidence in support of this notion is relatively limited. Most studies conducted in the context of acute and experimental pain, which seemingly demonstrated evidence for OIH, actually might have measured other phenomena such as acute opioid withdrawal or tolerance. ⋯ Thus far, with the exception of a few clinical case reports on OIH in patients with cancer pain and one prospective study in patients with chronic neuropathic pain, evidence for OIH in patients with chronic or cancer-related pain is lacking. Whether experimental pain models are necessary for establishing the clinical diagnosis of OIH, and which specific model is preferred, are yet to be determined.
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The objectives of this study are (1) to assess the presence of myofascial trigger points (TrPs) and widespread pressure hyperalgesia; and (2) to assess the relationship between the presence of active TrPs, pain intensity, and widespread pressure hypersensitivity in individuals with postmeniscectomy pain. ⋯ The referred pain elicited by active TrPs reproduced knee symptoms in patients with postmeniscectomy pain. Patients also showed localized reduction of PPT. The number of TrPs was associated with the intensity of pain and pressure hyperalgesia. Our findings suggest the presence of peripheral sensitization in patients with postmeniscectomy pain could be associated with the presence of active TrPs.
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Hormone replacement remains one of the common therapies for menopause-related pain but is associated with risk of orofacial or back pain. Spinal endomorphin-2 (EM-2) is involved in varied pain and its release is steroid-dependent, but whether increasing spinal EM-2 can inhibit thermal hyperalgesia and inflammatory pain in ovariectomized (OVX) female rats, an animal model mimicking menopause, is not clear, nor is the potential involvement of spinal mu-opioid receptor (MOR). In the current study, we revealed that the temporal decrease of spinal EM-2 is accompanied with OVX-induced thermal hyperalgesia that was dose-dependently attenuated by intrathecal (IT) delivery of EM-2. ⋯ Furthermore, IT delivery of EM-2 did not affect the animals' locomotion or anxiety status. Our findings suggested that IT EM-2 might be a safer analgesia strategy than hormone replacement therapy in reducing risk of orofacial or back pain. However, a long-lasting form of EM-2 with less tolerance is needed to induce sustained analgesia.