Pain
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Insomnia is a common problem for people with chronic pain. Cortical GABAergic neurons are part of the neurobiological substrate that underlies homeostatic sleep regulation. In the present study, we confirmed that sciatic nerve ligation caused thermal hyperalgesia and tactile allodynia in mice. ⋯ These findings provide novel evidence that sciatic nerve ligation decreases extracellular-released GABA in the cingulate cortex of mice. These phenomena may, at least in part, explain the insomnia in patients with neuropathic pain. Neuropathic pain-like stimuli suppress the GABAergic transmission with increased GABA (γ-aminobutyric acid) transporters located on activated astrocytes in the cingulate cortex related to sleep disturbance.
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No validated screening tasks exist to distinguish children who can accurately use self-report pain measures from those who cannot. Children aged 3-7 years (n=108), each with a parent, provided data before and after day surgery. Parents rated how well they thought their child could understand the Faces Pain Scale-Revised (FPS-R), and children completed 4 screening tasks in counterbalanced order, such as rating pain in vignettes and selecting a middle-sized cup. ⋯ We failed to identify a screening tool that was better than chronological age in identifying which children could accurately self-report pain using the FPS-R. Future research should explore other screening tasks, training methods, and simplified approaches to pain assessment for young children. The ability to use self-report pain scales usually develops from age 3 to 7 years, but no valid screening method exists to identify this achievement.
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Given the previous evidence for involvement of prostanoid EP1 receptors in facilitation of the bladder afferent nerve activity and micturition reflex, the present study investigated the effect of ONO-8130, a selective EP1 receptor antagonist, on cystitis-related bladder pain in mice. Cystitis in mice was produced by intraperitoneal administration of cyclophosphamide at 300mg/kg. Bladder pain-like nociceptive behavior and referred hyperalgesia were assessed in conscious mice. ⋯ Intravesical administration of prostaglandin E2 caused prompt phosphorylation of ERK in the L6 spinal cord, an effect blocked by ONO-8130. Our findings strongly suggest that the prostaglandin E2/EP1 system participates in processing of cystitis-related bladder pain, and that EP1 antagonists including ONO-8130 are useful for treatment of bladder pain, particularly in interstitial cystitis. Prostaglandin E2 contributes to cystitis-related bladder pain via EP1 receptors in mice, indicating possible therapeutic usefulness of selective EP1 antagonists.
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Excessive medication intake is a risk factor for the development of medication-overuse headache (MOH), a condition characterized by an increase of headache frequency to a daily or near-daily pattern. As yet, it is largely unknown why some patients overuse medication. In this study, we examined to what extent attitudes about pain medication, especially perceived need and concerns, and problem-solving are related to MOH. ⋯ Results are discussed in terms of how repeated attempts to solve pain may trigger overuse of medication, even in the presence of clear negative consequences. Repeated attempts at solving pain may increase the need for analgesic medication, despite obvious costs. This mechanism might contribute to the problem of medication-overuse headache.