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Virtual Reality (VR) is now consumer ready and nearing ubiquity. In terms of clinical applications, several studies suggest that VR can be effective as a complementary adjunct or alternative non-pharmacologic analgesic in a range of pain-inducing procedures and in management of chronic pain. The increasing affordability and quality of portable VR headsets and the ongoing utility of pain therapy signals an exciting future for the use of VR for analgesia. However, further research is needed to establish its long-term benefits if VR is to be adopted into mainstream protocols for analgesia management. This research requires a range of study designs with collection of patient self-report and clinical data together to develop bespoke interventions for different cohorts.
Learn More >Background Recent studies showed the possible association between inflammation-induced blood-brain barrier (BBB) structural changes followed by greater permeability of the BBB and chronic pain. Thus, measurement of BBB breakdown would be a valuable aid in the diagnosis in migraine. Dynamic contrast material-enhanced (DCE) MRI can determine perfusion and permeability properties related to the BBB. Purpose To evaluate the relationship between permeability of the BBB in migraine-associated brain regions by using DCE MRI. Materials and Methods In this prospective study, from September 2016 to December 2017, 56 study participants underwent DCE MRI after gadobutrol administration and were classified into migraine ( = 35) and healthy control ( = 21) groups. Automatic volumetric segmentation was performed on the pre-contrast-enhanced T1-weighted images by using FreeSurfer, and migraine-associated brain region masks were extracted by using the software NordicICE. The corresponding maps for pharmacokinetic parameters (the volume transfer constant) and (the fractional plasma volume) were coregistered with the region-of-interest masks, and their mean values of corresponding total volume of interest were calculated. For comparison analyses, the Mann-Whitney tests were used. Receiver operating characteristic curve analysis and Spearman rank correlation tests were used to identify correlations between clinical characteristics and the aforementioned perfusion parameters. Results Mean age was younger in the migraine group (mean ± standard deviation, 57 years ± 12) than in the healthy control group (mean, 71 years ± 8) ( < .001). In the migraine group, the mean value of in the left amygdala (median, 0.27 mL/100 g) was lower than that in the healthy control group (median, 0.39 mL/100 g) ( = .04). The mean value of in the left amygdala was correlated with the intensity of headache attack in participants with migraine (correlation coefficient, -0.34; = .04). Conclusion Lower fractional plasma volume in the left amygdala was observed in participants with migraine than in healthy participants. © RSNA, 2019 See also the editorial by Carroll and Ginat in this issue.
Learn More >In skin diseases and experimental models of pruritus, pure itch is accompanied by additional sensations that are poorly characterised.
Learn More >Inflammatory pain hypersensitivity is associated with activation of primary afferent neurons. The present study investigated the existence of the inflammasome in dorsal root ganglion (DRG) and the functional significance in the development of inflammatory pain hypersensitivity.Tissue inflammation was induced in male C57BL/6 mice with complete Freund's adjuvant (CFA) or ceramide injection into the hind paw. Behavioral testing was performed to investigate inflammation-induced pain hypersensitivity. Ipsilateral L5 DRG were obtained for analysis. Expression of nucleotide oligomerization domain-like receptors (NLRs) was analyzed with real-time PCR. Cleaved interleukin (IL)-1β and NLRP2 expression was investigated with immunohistochemistry and western blotting. Caspase1 activity was also measured. A caspase1 inhibitor and NLRP2 siRNA were intrathecally administered to inhibit NLRP2 inflammasome signaling in DRG.Cleaved IL-1β expression was significantly increased after CFA injection in small sized DRG neurons. The amount of cleaved IL-1β and caspase1 activity were also increased. Among several NLRs, NLRP2 mRNA was significantly increased in DRG after CFA injection. NLRP2 was expressed in small sized DRG neurons. Intrathecal injection of a caspase1 inhibitor or NLRP2 siRNA reduced CFA-induced pain hypersensitivity and cleaved IL-1β expression in DRG. Induction of cleaved IL-1β and NLRP2 in DRG neurons was similarly observed after ceramide injection. NLRP2 siRNA inhibited ceramide-induced pain hypersensitivity.These results confirmed the existence of NLRP2 inflammasome in DRG neurons. Activation of the NLRP2 inflammasome leads to activation of DRG neurons and subsequent development of pain hypersensitivity in various types of tissue inflammation.
Learn More >Previous literature suggests that ketamine may be an effective drug in the palliative care population as this drug has been shown to treat multiple conditions that are common in these patients. This review examines the efficacy of ketamine for the treatment of depression and physical pain in palliative care patients. Eleven studies were included on the topic of ketamine as an antidepressant in the palliative care population. Additionally, 5 RCT studies were included on the topic of physical pain in this population. All 11 studies, including one RCT, found antidepressant effects of ketamine in this patient population. Ketamine's effect on treating physical pain was mixed with the largest and most recent RCTs suggesting no significant analgesic effect. This review suggests that starting qualified patients on intravenous (IV) ketamine and switching to oral or intranasal administration may be the most effective and convenient for treating depression, especially for patients who wish to receive treatment at home. Significant analgesia was found in patients who received epidural or intrathecal ketamine as well as in one study using intravenous administration. More research is necessary to determine which palliative care patients may benefit from ketamine treatment.
Learn More >AbstarctPreviously, distinct sex differences were observed in the pronociceptive role of spinal immune cells in neuropathic and inflammatory mouse pain models. Both peripheral and central innate and adaptive immune changes contribute to sensitization in the tibia fracture rodent model of complex regional pain syndrome (CRPS), and the current study evaluated sex differences in the development of pronociceptive immune responses after fracture. At 4 and 7 weeks post fracture the analgesic effects of a microglia inhibitor were tested in male and female mice and PCR was used to measure inflammatory mediator expression in skin and spinal cord. The temporal progression of CRPS-like changes in male and female wild-type and muMT fracture mice lacking B cells and antibodies were evaluated and IgM antibody deposition measured. Pronociceptive effects of injecting wild-type fracture mouse serum into muMT fracture mice were also tested in both sexes and the role of sex hormones was evaluated in the post fracture development of pronociceptive immune responses. Long lasting immune changes developed in the fracture limb and corresponding spinal cord of both male and female mice, including upregulated neuropeptide and cytokine signaling, microglial activation, and pronociceptive autoimmunity. These complex post fracture immune responses were sexually dichotomous and interacted in temporally evolving patterns that generated post traumatic nociceptive sensitization in both sexes lasting for up to 5 months. Unfortunately, the redundancy and plasticity of these chronic post traumatic immune responses suggest that clinical interventions focusing on any single specific pronociceptive immune change are likely to be ineffectual.
Learn More >There is limited research on the association of sleep problems with International Classification of Headache Disorders (ICHD-II)-defined headache subtypes in youth, particularly from community-based samples. This cross-sectional study examines the associations of sleep patterns, symptoms and disorders with specific headache subtypes among adolescents from the general population of the United States.
Learn More >To determine whether the successful treatment of chronic migraine (CM) with onabotulinumA (BotoxA) may be followed by a continued respite from headache once therapy has been discontinued.
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