Search Results (8)

Pituitary adenylate cyclase-activating peptide (PACAP) is a neuropeptide expressed in the trigeminal ganglia (TG). The TG conducts nociceptive signals in the head and may play roles in migraine. PACAP infusion provokes headaches in healthy individuals and migraine-like attacks in patients; however, it is not clear whether targeting this system could be therapeutically efficacious. To effectively target the PACAP system, an understanding of PACAP receptor distribution is required. Therefore, this study aimed to characterize commercially available antibodies and use these to detect PACAP-responsive receptors in the TG. Antibodies were initially validated in receptor transfected cell models and then used to explore receptor expression in rat and human TG. Antibodies were identified that could detect PACAP-responsive receptors, including the first antibody to differentiate between the PAC_1n and PAC_1s receptor splice variants. PAC₁, VPAC₁, and VPAC₂ receptor-like immunoreactivity were observed in subpopulations of both neuronal and glial-like cells in the TG. In this study, PAC₁, VPAC₁, and VPAC₂ receptors were detected in the TG, suggesting they are all potential targets to treat migraine. These antibodies may be useful tools to help elucidate PACAP-responsive receptor expression in tissues. However, most antibodies exhibited limitations, requiring the use of multiple methodologies and the careful inclusion of controls. Full article

Background: Manual pressure in the upper cervical spine is used to provoke and reduce the familiar migraine headache. Information is scarce on the segmental levels, myofascial structure provocation, and reduction occurrences. The required dosage (amount of pressure, number of repetitions, and duration) has not been objectified yet. Methods: Prospective observational study. Thirty patients with migraine were examined interictally. Manual pressure was applied at four sites: the posterior arch of C1, the articular pillar of C2, the rectus capitis posterior major muscle, and the obliquus capitis inferior muscle, bilaterally. On sites where the familiar headache was provoked, the pressure was sustained to induce pain reduction (three repetitions). Provocation of familiar headache (yes/no), headache intensity (numerical pain rating scale), time to obtain a reduction of the headache (seconds), and applied pressure (g/cm²) were recorded. Results: Provocation of the familiar headache occurred at the posterior arches C1 in 92%, and at one of the articular pillars of C2 in 65.3% of cases. At one of the rectus capitis major muscles, the familiar headache was provoked in 84.6% of cases; at one of the oblique capitis inferior muscles, the familiar headache was provoked in 76.9% of cases. The applied mean pressure ranged from 0.82 to 1.2 kg/cm². Maintaining the pressure reduced headache pain intensity significantly between the start and end of each of the three consecutive trials (p < 0.04). This reduction occurred faster in the third application than in the first application (p = 0.03). Conclusion: Manual pressure at upper cervical segments provokes familiar referred migraine headaches, with low manual pressure. Maintaining the pressure reduces the referred head pain significantly, indicating modulation of central nociceptive transmission. Full article

Globally, migraine is a leading cause of disability with a huge impact on both the work and private life of affected persons. To overcome the societal migraine burden, better treatment options are needed. Increasing evidence suggests that ATP-sensitive potassium (K_ATP) channels are involved in migraine pathophysiology. These channels are essential both in blood glucose regulation and cardiovascular homeostasis. Experimental infusion of the K_ATP channel opener levcromakalim to healthy volunteers and migraine patients induced headache and migraine attacks in 82-100% of participants. Thus, this is the most potent trigger of headache and migraine identified to date. Levcromakalim likely induces migraine via dilation of cranial arteries. However, other neuronal mechanisms are also proposed. Here, basic K_ATP channel distribution, physiology, and pharmacology are reviewed followed by thorough review of clinical and preclinical research on K_ATP channel involvement in migraine. K_ATP channel opening and blocking have been studied in a range of preclinical migraine models and, within recent years, strong evidence on the importance of their opening in migraine has been provided from human studies. Despite major advances, translational difficulties exist regarding the possible anti-migraine efficacy of K_ATP channel blockage. These are due to significant species differences in the potency and specificity of pharmacological tools targeting the various K_ATP channel subtypes. Full article

Migraine headaches can be provoked by surgical stress and vasoactive effects of anesthetics of general anesthesia in the perioperative period. However, it is unclear whether general anesthesia increases the migraine risk after major surgery. Incidence and risk factors of postoperative migraine are also largely unknown. We utilized reimbursement claims data of Taiwan’s National Health Insurance and performed propensity score matching analyses to compare the risk of postoperative migraine in patients without migraine initially who underwent general or neuraxial anesthesia. Multivariable logistic regressions were applied to calculate the adjusted odds ratio (aOR) and 95% confidence interval (CI) for migraine risk. A total of 68,131 matched pairs were analyzed. The overall incidence of migraine was 9.82 per 1000 person-years. General anesthesia was not associated with a greater risk of migraine compared with neuraxial anesthesia (aORs: 0.93, 95% CI: 0.80–1.09). This finding was consistent across subgroups of different migraine subtypes, uses of migraine medications, and varying postoperative periods. Influential factors for postoperative migraine were age (aOR: 0.99), sex (male vs. female, aOR: 0.50), pre-existing anxiety disorder (aOR: 2.43) or depressive disorder (aOR: 2.29), concurrent uses of systemic corticosteroids (aOR: 1.45), ephedrine (aOR: 1.45), and theophylline (aOR: 1.40), and number of emergency room visits before surgery. There was no difference in the risk of postoperative migraine between surgical patients undergoing general and neuraxial anesthesia. This study identified the risk factors for postoperative migraine headaches, which may provide an implication in facilitating early diagnoses and treatment. Full article

Visual sensations appear in most migraine auras, but binocular blindness is uncommon. We described a case of multiple transient losses of vision in a man on a winter expedition to K2. His symptoms were later diagnosed as recurrent visual auras without pain. Sojourns at altitude can induce migraine attack; therefore, susceptible individuals should avoid factors that might provoke migraines at high altitude, such as improper acclimatization, dehydration and an inadequate sleep regime. Full article

Background: There is a growing realization that the gut–brain axis signaling is critical for maintaining the health and homeostasis of the Central Nervous System (CNS) and the intestinal environment. The role of Short-Chain Fatty Acids (SCFAs), such as Sodium Propionate (SP) and Sodium Butyrate (SB), has been reported to counteract inflammation activation in the central and Enteric Nervous System (ENS). Methods: In this study, we evaluated the role of the SCFAs in regulating the pathophysiology of migraine and correlated dysregulations in the gut environment in a mouse model of Nitroglycerine (NTG)-induced migraine. Results: We showed that, following behavioral tests evaluating pain and photophobia, the SP and SB treatments attenuated pain attacks provoked by NTG. Moreover, treatments with both SCFAs reduced histological damage in the trigeminal nerve nucleus and decreased the expression of proinflammatory mediators. Ileum evaluation following NTG injection reported that SCFA treatments importantly restored intestinal mucosa alterations, as well as the release of neurotransmitters in the ENS. Conclusions: Taken together, these results provide evidence that SCFAs exert powerful effects, preventing inflammation through the gut–brain axis, suggesting a new insight into the potential application of SCFAs as novel supportive therapies for migraine and correlated intestinal alterations. Full article

Migraine, the leading cause of disability in the population aged below 50, is associated with functional gastrointestinal (GI) disorders (FGIDs) such as functional nausea, cyclic vomiting syndrome, and irritable bowel syndrome (IBS). Conversely, changes in intestinal GI transit may cause diarrhea or constipation and are a component of the autonomic symptoms associated with pre- and post-dorsal phases of migraine attack. These mutual relationships provoke a question on a common trigger in migraine and FGIDs. The kynurenine (l-kyn) pathway (KP) is the major route for l-tryptophan (l-Trp) metabolism and transforms l-Trp into several neuroactive compounds. Changes in KP were reported in both migraine and FGIDs. Migraine was largely untreatable, but several drugs approved lately by the FDA, including monoclonal antibodies for calcitonin gene-related peptide (CGRP) and its receptor, create a hope for a breakthrough in migraine treatment. Derivatives of l-kyn were efficient in pain relief with a mechanism including CGRP inhibition. KP products are important ligands to the aryl hydrocarbon receptor (AhR), whose activation is implicated in the pathogenesis of GI and migraine. Toll-like receptors (TLRs) may play a role in migraine and IBS pathogeneses, and KP metabolites detected downstream of TLR activation may be an IBS marker. The TLR4 signaling was observed in initiating and maintaining migraine-like behavior through myeloid differentiation primary response gene 88 (MyD88) in the mouse. The aim of this review is to justify the view that KP modulation may provide common triggers for migraine and FGIDs with the involvement of TLR, AhR, and MyD88 activation. Full article

(1) Background: Visually induced vertigo (i.e., vertigo provoked by moving visual scenes) can be considered a noticeable feature of vestibular migraines (VM) and can be present in patients suffering from acute unilateral vestibulopathy (AUV). Hypersensitivity to moving or conflicting visual stimulation is named visual dependence. (2) Methods: Visuo-vestibular interactions were analyzed via the functional Head Impulse Test (fHIT) with and without optokinetic stimulation (o-fHIT) in 25 patients with VM, in 20 subjects affected by AUV, and in 20 healthy subjects. We calculated the percentage of correct answers (%CA) without and with the addition of the optokinetic background (OB). (3) In VM groups, the %CA on the fHIT was 92.07% without OB and 73.66% with OB. A significant difference was found between %CA on the deficit side and that on the normal side in AUV, both without OB and with OB. (4) Conclusions: The fHIT results in terms of %CA with and without OB could be useful to identify the presence of a dynamic visual dependence, especially in patients suffering from VM. The difference in %CA with and without OB could provide instrumental support to help correctly identify subjects suffering from VM. We propose the use of the fHIT in clinical practice whenever there is a need to highlight a condition of dynamic visual dependence. Full article