The journal of pain : official journal of the American Pain Society
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Vestibulodynia is characterized by perivaginal mechanical hypersensitivity, hyperinnervation, and abundant inflammatory cells expressing renin-angiotensin system proteins. We developed a tractable rat model of vestibulodynia to further assess the contributions of the renin-angiotensin system. Complete Freund's adjuvant injected into the posterior vestibule induced marked vestibular hypersensitivity throughout a 7-day test period. ⋯ Media conditioned with inflamed vestibular tissue promoted neurite sprouting by rat dorsal root ganglion neurons in vitro, and this was blocked by the angiotensin II receptor type 2 receptor antagonist PD123319 or by an angiotensin II function blocking antibody. Sensory axon sprouting induced by inflamed tissue was dependent on activity of angiotensin-converting enzyme or chymase, but not cathepsin G. Thus, vestibular Complete Freund's adjuvant injection substantially recapitulates changes seen in patients with provoked vestibulodynia, and shows that manipulation of the local inflammatory renin-angiotensin system may be a useful therapeutic strategy.
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Only one published study has investigated the effect of a threatening social context on the perception and expression of pain, showing that social threat leads to increased pain reports but reduced nonverbal pain expression. The current study aimed to replicate and extend these findings to further explore the effects of a threatening social context. Healthy, female participants (N = 71) received 10 electrocutaneous stimuli delivered by a confederate. ⋯ Moreover, perceived social threat predicted the threat value of pain and reduced empathy toward the confederate. We were not able to replicate the previously reported dissociation between pain reports and pain expression as a result of social threat. However, social threat was associated with an increased threat value of pain, increased aggression, and reduced empathy.
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Many factors interact to influence threat perception and the subsequent experience of pain. This study investigated the effect of observing pain (extrinsic threat) and intrinsic threat of pain to oneself on pressure pain threshold (PPT). Forty socially connected pairs of healthy volunteers were threat-primed and randomly allocated to experimental or control roles. ⋯ A significant increase in PPT between "baseline 2" and "pre-immersion" was seen (t = -7.6, P = .005), a pain modulatory effect of 25.8 ± 20.7%. Extrinsic and intrinsic threat of pain, in the absence of any afferent input therefore influences pain modulation. This may need to be considered in studies that use noxious afferent input with populations who show dysfunctional pain modulation.
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Prescription drug monitoring programs (PDMPs) are a response to the prescription opioid epidemic, but their effects on prescribing and health outcomes remain unclear, with conflicting reports. We sought to determine if prescriber use of Oregon's PDMP led to fewer high-risk opioid prescriptions or overdose events. We conducted a retrospective cohort study from October 2011 through October 2014, using statewide PDMP data, hospitalization registry, and vital records. ⋯ However, compared with nonregistrants, PDMP registrants did not subsequently have significantly fewer patients receiving high-dose prescriptions, overlapping opioid and benzodiazepine prescriptions, inappropriate prescriptions, prescriptions from multiple prescribers, or overdose events. At baseline, frequent PDMP users wrote fewer high-risk opioid prescriptions than infrequent users; this persisted during follow-up with few significant group differences in trend. Thus, although opioid prescribing declined statewide after implementing the PDMP, registrants did not show greater declines than nonregistrants.
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The heterogeneity of the clinical presentation and the pathophysiologic mechanisms associated with fibromyalgia (FM), and the modest results on average for any therapy, call for a more individualized management strategy. Individualized treatment can be on the basis of subgrouping of patients according to associated conditions (mental health problems, chronic overlapping pain conditions, other somatic diseases) or on disease severity. Categorizing FM as mild, moderate, or severe can be on the basis of clinical assessment (eg, degree of daily functioning) or on questionnaires. ⋯ The European League Against Rheumatism guidelines recommend a tailored approach directed by FM key symptoms (pain, sleep disorders, fatigue, depression, disability), whereas the German guidelines recommend management tailored to disease severity, with mild disease not requiring any specific treatment, and more severe disease requiring multicomponent therapy (combination of drug treatment with aerobic exercise and psychological treatments). When indicated, treatments should follow a stepwise approach beginning with easily available therapies such as aerobic exercise and amitriptyline. Successful application of a tailored treatment approach that is informed by individual patient characteristics should improve outcome of FM.