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Interdisciplinary cognitive behavioral therapy (CBT) for chronic pain is effective at improving function, mood, and pain interference among individuals with disabling chronic pain. Traditionally, CBT assumes cognitive change is an active therapeutic ingredient in the determination of treatment outcome. Pain catastrophizing, a cognitive response style that views the experience of pain as uncontrollable, permanent, and destructive, has been identified as an important maladaptive cognition which contributes to difficulties with the management of chronic pain. Consequently, pain catastrophizing is commonly targeted in CBT for chronic pain.
Learn More >Oral cancer patients often have severe, chronic, and mechanically induced pain at the site of the primary cancer. Oral cancer pain is initiated and maintained in the cancer microenvironment and attributed to release of mediators that sensitize primary sensory nerves. This study was designed to investigate the histopathology associated with painful oral cancers in a preclinical model. The relationship of pain scores with pathologic variables was also investigated in a cohort of 72 oral cancer patients. Wild-type mice were exposed to the carcinogen, 4-nitroquinoline 1-oxide (4NQO). Nociceptive (pain) behavior was measured with the dolognawmeter, an operant device and assay for measuring functional and mechanical allodynia. Lesions developed on the tongues and esophagi of the 4NQO-treated animals and included hyperkeratoses, papillomas, dysplasias, and cancers. Papillomas included lesions with benign and dysplastic pathological features. Two histologic subtypes of squamous cell carcinomas (SCCs) were identified-SCCs with exophytic and invasive components associated with papillary lesions (pSCCs) and invasive SCCs without exophytic histology (iSCCs). Only the pSCC subtype of tongue cancer was associated with nociceptive behavior. Increased tumor size was associated with greater nociceptive behavior in the mouse model and more pain experienced by oral cancer patients. In addition, depth of invasion was associated with patient-reported pain. The pSCC histology identifies 4NQO-induced tongue cancers that are expected to be enriched for expression and release of nociceptive mediators.
Learn More >Propranolol is a nonselective β-adrenergic receptor antagonist that is efficacious in reducing facial pain. There is evidence that its analgesic efficacy might be modified by variants of the catechol-O-methyltransferase () gene. We tested the hypothesis in a subset of 143 non-Hispanic Whites from a randomized controlled trial of patients with painful temporomandibular disorder (TMD). Patients were genotyped for rs4680, a single nucleotide polymorphism of , and randomly allocated to either propranolol 60 mg twice daily or placebo. During the 9-wk follow-up period, patients recorded daily ratings of facial pain intensity and duration; the product was computed as an index of facial pain. Postbaseline change in the index at week 9 (the primary endpoint) was analyzed as a continuous variable and dichotomized at thresholds of ≥30% and ≥50% reduction. Mixed models for repeated measures tested for the genotype × treatment group interaction and estimated means, odds ratios (ORs), and 95% confidence limits (95% CLs) of efficacy within genotypes assuming an additive genetic model. In secondary analysis, the cumulative response curves were plotted for dichotomized reductions ranging from ≥20% to ≥70%, and genotype differences in area under the curve percentages (%AUC) were calculated to signify efficacy. Mean index reduction did not differ significantly ( = 0.277) according to genotype, whereas the dichotomized ≥30% reduction revealed greater efficacy among G:G homozygotes (OR = 10.9, 95%CL = 2.4, 50.7) than among A:A homozygotes (OR = 0.8, 95%CL = 0.2, 3.2) with statistically significant interaction ( = 0.035). Cumulative response curves confirmed greater ( = 0.003) efficacy for G:G homozygotes (%AUC difference = 43.7, 95%CL = 15.4, 72.1) than for A:A homozygotes (%AUC difference = 6.5, 95%CL = -30.2, 43.2). The observed antagonistic effect of the A allele on propranolol's efficacy was opposite the synergistic effect hypothesized a priori. This unexpected result highlights the need for better knowledge of role in pain pathogenesis if the gene is to be used for precision-medicine treatment of TMD (ClinicalTrials.gov NCT02437383).
Learn More >Complex regional pain syndrome (CRPS) is a complex and often poorly understood condition, and people with CRPS will have diverse beliefs about their symptoms. According to the self-regulation model, these beliefs (termed "illness perceptions") influence health behaviors and outcomes. Previous studies have found that psychological factors influence CRPS outcomes, but few studies have investigated CRPS patients' illness perceptions specifically. The present study examined whether illness perceptions were related to pain intensity and other relevant outcomes in people with CRPS.
Learn More >To analyze a series of novel non-invasive urinary biomarkers for their ability to objectively monitor the longitudinal clinical status of UCPPS patients.
Learn More >The double-blind, phase 3 PREEMPT trials demonstrated the efficacy and tolerability of onabotulinumtoxinA for headache prevention in adults with chronic migraine. This post hoc analysis evaluated the effect of onabotulinumtoxinA on clinically meaningful changes in headache severity, headache-related impact, and quality of life.
Learn More >Not all factors that predict persistent pain and disability following whiplash injury are known. In particular, few physical factors, such as changes in movement and muscle behaviour, have been investigated. The aim of this study is to identify predictive factors that are associated with the development of persistent pain and disability following a whiplash injury by combining contemporary measures of physical function together with established psychological and pain-related predictive factors.
Learn More >The phase 3 PREEMPT trials demonstrated efficacy and tolerability of onabotulinumtoxinA for headache prevention in adults with chronic migraine. OnabotulinumtoxinA significantly reduced headache frequency from baseline vs. placebo at 24 weeks; however, this measure may not fully capture the benefits of treatment. We evaluated the impact of onabotulinumtoxinA on patient-reported outcomes according to headache responder status.
Learn More >Slowly depolarizing currents applied for 1 min have been shown to activate C-nociceptors and provoke increasing pain in patients with neuropathy. This study examined the effect of transcutaneous slowly depolarizing currents on pruritus in patients with atopic dermatitis. C-nociceptor-specific electrical stimu-lation was applied to areas of eczema-affected and non-affected skin in 26 patients with atopic dermatitis. Single half-sine wave pulses (500 ms, 0.2-1 mA) induced itch in 9 patients in the eczema (numerical rating scale 5 ± 1), but pain in control skin (numerical rating scale 6 ± 1). Sinusoidal stimuli (4 Hz, 10 pulses, 0.025-0.4 mA) evoked itch in only 3 patients, but on delivering pulses for 1 min (0.05-0.2 mA) approximately 50% of the patients (n = 12) reported itch with numerical rating scale 4 ± 1 in areas of eczema-affected skin. The number of patients reporting itch increased with longer stimulation (p < 0.005). These results indicate a reduced adaptation of peripheral C-fibres conveying itch in patients with AD. Also, sensitized spinal itch processing may underlie chronic itch in these patients, who might benefit from centrally acting antipruritic therapy.
Learn More >Pruritus is one of the leading symptoms of dermatitis herpetiformis (DH), however, studies on the pathogenesis of pruritus are scarce. Currently, skin mast cells (MCs) have been indicated to play a role in pruritus in autoimmune bullous disease.
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