Pain
-
Review
Experimental pain processing in individuals with cognitive impairment: current state of the science.
Cognitive impairment (CI) can develop during the course of ageing and is a feature of many neurological and neurodegenerative diseases. Many individuals with CI have substantial, sustained, and complex health care needs, which frequently include pain. However, individuals with CI can have difficulty communicating the features of their pain to others, which in turn presents a significant challenge for effective diagnosis and treatment of their pain. ⋯ Our current understanding of the neurobiological mechanisms underpinning these alterations is limited but may be enhanced through the use of animal models of CI, which also exhibit alterations in nociceptive responding. Further research using additional behavioural indices of pain is warranted. Increased understanding of altered experimental pain processing in CI will facilitate the development of improved diagnostic and therapeutic approaches for pain in individuals with CI.
-
It is believed that patients' expectancies about the effectiveness of treatment influence their treatment outcomes, but the working mechanism is rarely studied in patients with low back pain. Theoretical models suggest that adherence to treatment may be an important pathway. The aim of this study was to assess the mediating role of adherence to treatment in the relationship between expectancies and the outcomes of recovery and pain intensity in patients with acute low back pain. ⋯ A total of 1573 participants were included in current analyses. There was a small but highly significant relationship between expectancies and outcomes; 3.3% of the relationship between expectancies and recovery and 14.2% of the relationship between expectancies and pain intensity were mediated by adherence to treatment. This study does not convincingly support the theory that adherence is a key pathway in the relationship between treatment outcome expectancies and recovery and pain intensity in this acute low back pain population.
-
Each year, millions of people worldwide are treated for primary or recurrent pelvic malignancies, involving radiotherapy in almost 50% of cases. Delayed development of visceral complications after radiotherapy is recognized in cancer survivors. Therapeutic doses of radiation may lead to the damage of healthy tissue around the tumor and abdominal pain. ⋯ Finally, intravenous injection of 1.5 million MSCs, 4 weeks after irradiation, induced a time-dependent reversion of the visceral allodynia and a reduction of the number of anatomical interactions between mast cells and PGP9.5+ nerve fibers. Moreover, unlike ketotifen, MSC treatment has the key advantage to limit radiation-induced colonic ulceration. This work provides new insights into the potential use of MSCs as cellular therapy in the treatment of pelvic radiation disease.
-
Activated mammalian target of rapamycin (P-mTOR) has been shown to maintain the sensitivity of subsets of small-diameter primary afferent A-nociceptors. Local or systemic inhibition of the mTOR complex 1 (mTORC1) pathway reduced punctate mechanical and cold sensitivity in neuropathic pain and therefore offered a new approach to chronic pain control. In this study, we have investigated the effects of the rapamycin analog temsirolimus (CCI-779) on itch. ⋯ We also examined the colocalization of P-mTOR with gastrin-releasing peptide, a putative marker for some itch-sensitive primary afferents, and found that P-mTOR was coexpressed in less than 5% of gastrin-releasing peptide-positive fibers in the mouse skin. Taken together, the data highlight the role that P-mTOR-positive A-fibers play in itch signaling and underline the importance of the mTORC1 pathway in the regulation of homeostatic primary afferent functions such as pain and itch. The actions of the antidiabetic drug metformin in ameliorating nonhistamine-mediated itch also suggest a new therapeutic route for the control of this category of pruritus.
-
Randomized Controlled Trial
Combination of morphine with nortriptyline for neuropathic pain.
First-line neuropathic pain drugs, including tricyclic antidepressants, are not always effective, and opioids have been recommended as second line. This trial evaluates a nortriptyline-morphine combination, compared with each monotherapy. In this randomized, double-blind crossover trial, patients with neuropathic pain were enrolled at 1 site between January 25, 2010, and May 22, 2014, and randomized in a 1:1:1 ratio using a balanced Latin square design to receive oral nortriptyline, morphine, and their combination. ⋯ Combination treatment resulted in moderate-severe constipation in 43% vs 46% with morphine (P = 0.82) and 5% with nortriptyline (P < 0.0001). Combination treatment resulted in moderate-severe dry mouth in 58% vs 49% with nortriptyline (P = 0.84) and 13% with morphine (P < 0.0001). This trial suggests superior efficacy of a nortriptyline-morphine combination over either monotherapy with constipation, dry mouth, and somnolence as the most frequent adverse effects.