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Ubrogepant is an oral calcitonin gene-related peptide receptor antagonist under investigation for acute treatment of migraine.
Learn More >To determine the relationship between hormonal contraceptive (HC) use and painful symptoms, particularly those associated with headache and painful temporomandibular disorders (TMD).
Learn More >Knee pain in osteoarthritis is complex and complicated by the fact that osteoarthritis is considered to be a disorder of multiple phenotypes. This complexity challenges our understanding as to why some people remain relatively symptom-free, while others progress to persistent pain. One approach to understanding the mechanisms underlying the transition to persistent pain is by identifying pain susceptibility phenotypes in people with or at risk of knee osteoarthritis. Using variables representative of the multidimensional nature of pain in people who were free of persistent pain, we identified four phenotypes characterised by low pressure pain thresholds and temporal summation and not psychosocial factors in those who developed persistent pain two years later. The group with the highest proportion of low pressure pain thresholds and a moderate proportion with facilitated temporal summation had twice the odds of developing persistent knee pain. This work provides preliminary insights into the critical importance of altered neurobiological mechanisms of pain signalling that contributes to development of chronic, persistent pain in knee osteoarthritis.
Learn More >Opioid-related deaths continue to increase in North America, an epidemic that was initiated by high rates of opioid prescribing. We designed a multifaceted, theory-informed Opioid Self-Assessment (OSA) package, to increase adherence to the Canadian Opioid Guideline among family physicians. This study aimed to assess changes in Canadian family physicians' knowledge and practices after completing the OSA package.
Learn More >Slow deep breathing (SDB) is commonly employed in the management of pain, but the underlying mechanisms remain equivocal. This study sought to investigate effects of instructed breathing patterns on experimental heat pain and to explore possible mechanisms of action. In a within-subject experimental design, healthy volunteers (n = 48) performed four breathing patterns: 1) unpaced breathing (UB), 2) paced breathing at the participant's spontaneous breathing frequency (PB), 3) SDB at six breaths per minute with a high inspiration/expiration ratio (SDB-H), and 4) SDB at six breaths per minute with a low inspiration/expiration ratio (SDB-L). During presentation of each breathing pattern, participants received painful heat stimuli of three different temperatures and rated each stimulus on pain intensity. Respiration, heart rate, and blood pressure were recorded. Compared to UB, participants reported less intense pain during each of the three instructed breathing patterns. Among the instructed breathing patterns, pain did not differ between PB and SDB-H, and SDB-L attenuated pain more than the PB and SDB-H patterns. The latter effect was paralleled by greater blood pressure variability and baroreflex effectiveness index during SDB-L. Cardiovascular changes did not mediate the observed effects of breathing patterns on pain. Perspective: SDB is more efficacious to attenuate pain when breathing is paced at a slow rhythm with an expiration that is long relative to inspiration, but the underlying mechanisms remain to be elucidated.
Learn More >To characterize phenotypes of a novel CACNA1A mutation causing familial hemiplegic migraine type 1.
Learn More >Nausea and vomiting are often associated with opioid analgesia in cancer patients; however, only a subset of patients develop such side effects. Here, we tested the hypothesis that the occurrence of nausea and vomiting is modulated by the genetic background of the patients. Whole exome sequencing of DNA pools from patients with either low (n = 937) or high (n = 557) nausea and vomiting intensity, recruited in the European Pharmacogenetic Opioid Study, revealed a preliminary association of 53 polymorphisms. PCR-based genotyping of 45 of these polymorphisms in the individual patients of the same series confirmed the association for six SNPs in AIM1L, CLCC1, MUC16, PDE3A, POM121L2, and ZNF165 genes. Genotyping of the same 45 polymorphisms in 264 patients of the Italian CERP study, also treated with opioids for cancer pain, instead confirmed the association for two SNPs in ZNF568 and PDE3A genes. Only one SNP, rs12305038 in PDE3A, was confirmed in both series, although with opposite effects of the minor allele on the investigated phenotype. Overall, our findings suggest that genetic factors are indeed associated with nausea and vomiting in opioid-treated cancer patients, but the role of individual polymorphisms may be weak.
Learn More >To investigate the functional connectivity (FC) in nonacute sciatica and the neuronal correlation of acupuncture analgesia.
Learn More >Ketamine has recently emerged as a promising therapeutic alternative for abortive migraine therapy, likely secondary to N-methyl-d-aspartate antagonism. Most reports examine adults and the intravenous route. Fewer utilize intranasal administration or pediatric populations. Given the limited evidence for intranasal ketamine in pediatric migraine populations, we retrospectively reviewed our experience to further characterize safety and efficacy of intranasal ketamine in this population.
Learn More >The evolution of peripheral and central changes following a peripheral nerve injury imply the onset of afferent signals that affect the brain. Changes to inflammatory processes may contribute to peripheral and central alterations such as altered psychological state and are not well characterized in humans. We focused on four elements that change peripheral and central nervous systems following ankle injury in 24 adolescent patients and 12 age-sex matched controls. Findings include (a) Changes in tibial, fibular, and sciatic nerve divisions consistent with neurodegeneration; (b) Changes within the primary motor and somatosensory areas as well as higher order brain regions implicated in pain processing; (c) Increased expression of fear of pain and pain reporting; and (d) Significant changes in cytokine profiles relating to neuroinflammatory signaling pathways. Findings address how changes resulting from peripheral nerve injury may develop into chronic neuropathic pain through changes in the peripheral and central nervous system.
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