Pain
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Enriched enrolment, randomised withdrawal (EERW) pain trials select, before randomisation, patients who respond by demonstrating a predetermined degree of pain relief and acceptance of adverse events. There is uncertainty over the value of this design. We report a systematic review of EERW trials in chronic noncancer pain together with a critical appraisal of methods and potential biases in the methods used and recommendations for the design and reporting of future EERW trials. ⋯ Shorter, small studies can be explanatory; longer, larger studies can inform practice. Current evidence is inadequate for valid comparisons in outcome between EERW and classical trials, although no gross differences were found. This systematic review provides a framework for assessing potential biases and the value of the EERW trials, and for the design of future studies by making recommendations for the conduct and reporting of EERW trials.
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A systematic review was conducted to identify and summarize the available scientific literature addressing pressure pain threshold (PPT) values over the temporalis, masseter, and frontalis muscles in healthy humans, patients with tension-type headache (TTH), and those with migraine both in males and females. Six relevant medical databases for the literature search were included: PubMed, Web of Science, Cochrane, CINAHL, BioMed Central, and Embase. The search strategy was performed applying 15 keywords (eg, pressure pain threshold, temporalis muscle, tension type headache, pressure algometer) and their combinations. ⋯ Females had lower PPT values than those of males in temporalis, masseter, and frontalis muscles. This work is the first to systematically review the scientific literature addressing PPT values over craniofacial muscles of healthy subjects, patients with TTH, and those with migraine to provide the PPT value ranges. Based on these findings, a set of guidelines was established to assist future studies including PPT assessments over craniofacial muscles.
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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.
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Moderate to severe chronic pain is a problem for 1.7 million children, costing $19.5 billion dollars annually in the United States alone. Risk-stratified care is known to improve outcomes in adults with chronic pain. However, no tool exists to stratify youth who present with pain complaints to appropriate interventions. ⋯ Risk groups did not significantly differ by pain diagnosis, location, or duration. Only 2% to 7% of patients who met reference standard case status for disability and emotional distress at 4-month follow-up were classified as low risk at baseline, whereas 71% to 79% of patients who met reference standard case status at follow-up were classified as high risk at baseline. A 9-item screening tool identifying factors associated with adverse outcomes among youth who present with pain complaints seems valid and provides risk stratification that can potentially guide effective pain treatment recommendations in the clinic setting.
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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.