Cephalalgia : an international journal of headache
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Development and characterization of a novel injury-free preclinical model of migraine-like pain allowing mechanistic assessment of both acute and preventive treatments. ⋯ We have developed a novel injury-free model with translational relevance that can be used to study mechanisms relevant to migraine-like pain and to evaluate novel acute or preventive treatments. Restraint stress priming induced a state of vulnerability to a subthreshold stimulus that has been referred to as "latent sensitization". The development of latent sensitization could be prevented by blockade of stress pathways with propranolol or with a kappa opioid receptor antagonist. Following establishment of latent sensitization, subthreshold stimulation with umbellulone reinstated cutaneous allodynia, likely from activation of meningeal TRPA1-expressing nociceptors. Accordingly, in restraint stress-primed animals, sumatriptan reversed umbellulone-induced cutaneous allodynia, supporting peripheral sites of action, while propranolol and nor-BNI were not effective. Surprisingly, olcegepant was effective in mice with latent sensitization when given prior to, but not after, umbellulone challenge, suggesting time-dependent contributions of calcitonin gene-related peptide receptor signaling in promoting migraine-like pain in this model. Activation of the calcitonin gene-related peptide receptor participates in initiating, but has a more limited role in maintaining, pain responses, supporting the efficacy of small molecule calcitonin gene-related peptide antagonists as preventive medications. Additionally, the effectiveness of sumatriptan in reversal of established pain thus suggests modulation of additional, non-calcitonin gene-related peptide receptor-mediated nociceptive mechanisms. Kappa opioid receptor antagonists may represent a novel preventive therapy for stress-related migraine.
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The Clinical Trials Subcommittee of the International Headache Society presents the first Health Technology Assessment for the Acute Treatment of Migraine Attacks and Prevention of Migraine. Health technology assessments are systematic evaluations of the properties, effects, and consequences of healthcare technologies; this position statement is designed to inform decision makers about access to and reimbursement for medications and devices for the acute and preventive treatment of migraine. This position statement extends beyond the already available guidelines on randomized controlled trials for migraine to incorporate real-world evidence and a synthetic approach for considering multiple data sources and modelling methods when assessing the value of migraine treatments.