Sex differences in CGRP-induced vasodilation of human middle meningeal arteries but not human coronary arteries: implications for migraine.

BACKGROUND: Migraine prevalence and levels of calcitonin gene-related peptide (CGRP), a peptide involved in migraine pathophysiology, differ between men and women, and appear to be affected by changes in sex hormones. The present study investigated the sex-specific responses to CGRP in human isolated arteries. METHODS: CGRP-induced relaxation of 62 (28 men and 34 women) human isolated middle meningeal arteries (HMMA) and 139 (69 men and 70 women) human isolated coronary arteries (HCA) was compared between men and women in groups <50 years and ≥50 years of age as a proxy for pre- and postmenopausal status in women, as well as matched-age groups for men. RESULTS: In HCA, no differences were observed between male and female tissue, or between the different age groups. However, in HMMA, the maximum response was significantly smaller and CGRP was less potent in females <50 compared with males <50 years of age. No differences were observed between the older age groups. CONCLUSIONS: Sex differences were observed for CGRP-induced relaxation of HMMA, but not HCA. These differences could arise from differential receptor expression in the vascular beds combined with the effect of sex hormones on CGRP and subsequent receptor desensitization.

European Headache Federation (EHF) critical re-appraisal and meta-analysis of oral drugs in migraine prevention - part 4: propranolol.

OBJECTIVE: The aim of this paper is to critically re-appraise the published trials assessing propranolol for migraine prophylaxis. METHODS: We report methods and results following the Preferred Reporting Items for Systematic Reviews (PRISMA), by searching MEDLINE, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov for randomized trials of pharmacologic treatments for migraine prophylaxis. We included randomized trials that compared propranolol with placebo for migraine prophylaxis in adults. The outcomes of interest were informed by the Core outcome set for preventive intervention trials in chronic and episodic migraine (COSMIG) and include the proportion of patients who experience a 50% or more reduction in monthly migraine days, the reduction of monthly migraine days, and the number of adverse events leading to discontinuation. We assessed risk of bias by using a modified Cochrane RoB (risk of bias) 2.0 tool and the certainty of evidence by using the GRADE approach. RESULTS: Our search yielded twenty trials (n = 1291 patients) eligible for data synthesis and analysis. The analysis revealed a moderate certainty evidence that propranolol leads to a reduction in monthly migraine days versus placebo (-1.27; 95% CI: -2.25 to -0.3). We found moderate certainty evidence that propranolol increases the proportion of patients who experience a 50% or more reduction in monthly migraine days, compared to placebo with a relative risk of 1.65 (95% CI 1.41 to 1.93); absolute risk difference: 179 more per 1,000 (95% CI 113 to 256). We found high certainty evidence that propranolol increases the proportion of patients who discontinue due to adverse events compared to placebo with a risk difference of 0.02 (95% CI 0.00 to 0.03); absolute risk difference: 20 more per 1,000 (95% CI 0 to 30). CONCLUSIONS: The present meta-analysis shows that propranolol has a prophylactic role in migraine, with an overall acceptable tolerability profile. Combining these results with its long-standing use and its global availability at a low cost confirms its role as a first line agent in the prophylaxis of migraine.

Sex-Specific Association of Cardiovascular Risk Factors With Migraine: The Population-Based Rotterdam Study.

BACKGROUND AND OBJECTIVES: Although several lines of evidence suggest a link between migraine and cardiovascular events, less is known about the association between cardiovascular risk factors (CVRFs) and migraine. This knowledge is clinically important to provide directions on mitigating the cardiovascular risk in patients with migraine. We hypothesized that CVRFs are associated with a higher migraine prevalence. Therefore, our primary objective was to investigate sex-specific associations between CVRFs and lifetime prevalence of migraine. METHODS: We performed cross-sectional analyses within an ongoing population-based cohort study (Rotterdam Study), including middle-aged and elderly individuals. By means of (structured) interviews, physical examinations, and blood sampling, we obtained information on the lifetime prevalence of migraine and the following traditional CVRFs: current smoking, obesity, hypercholesterolemia, hypertension, and diabetes mellitus. Similarly, we obtained information on quantitative component data on these CVRFs, including pack-years of smoking, lipid levels, systolic and diastolic blood pressure (BP), body mass index, and fasting glucose levels. Patients with migraine were age-matched to individuals without migraine, and we performed conditional logistic regression analyses to investigate the sex-stratified association of CVRFs with migraine. RESULTS: In total, 7,266 community-dwelling middle-aged and elderly persons were included (median age 66.6 [IQR 56.4-74.8] years, 57.5% females). The lifetime prevalence of migraine was 14.9%. In females, current smoking (odds ratio (OR) 0.72, 95% CI 0.58-0.90), more pack-years (OR per SD increase 0.91, 95% CI 0.84-1.00), diabetes mellitus (OR 0.74, 95% CI 0.56-0.98), and higher fasting glucose levels (OR per SD increase in glucose 0.90, 95% CI 0.82 - 0.98) were all related to a lower migraine prevalence while a higher diastolic BP related to a higher migraine prevalence (OR per SD increase 1.16, 95% CI 1.04-1.29). In males, no significant associations between CVRFs and migraine were observed. DISCUSSION: Traditional CVRFs were either unrelated or inversely related to migraine in middle-aged and elderly individuals, but only in females. In males, we did not find any association between CVRFs and migraine. Because only an increased diastolic BP was related to a higher migraine prevalence in females, our study contributes to the hypothesis that migraine is not directly associated with traditional CVRFs. Future studies are warranted to extrapolate these findings to younger populations.

Changes in Migraine Symptoms after Ischemic Stroke: A Cohort Study.

INTRODUCTION: Migraine symptoms are postulated to improve post-stroke. We aimed to determine post-stroke changes in patients with active migraine pre-stroke and explored the relation with stroke location and stroke-preventive medication use. METHODS: Patients with active migraine who had an ischemic stroke were retrieved from three research-cohorts between 2014 and 2021. By an interview, we retrospectively investigated first-year post-stroke changes for those ischemic stroke patients that suffered from migraine pre-stroke. Associations between change in migraine frequency/intensity/aura (decrease, no change, increase), stroke location (posterior location vs. other), and use of secondary stroke preventive medication were assessed by ordinal regression with adjustment for confounders. RESULTS: We included 78 patients (mean age 48 years, 86% women, 47% with aura). Change in migraine symptomatology was reported by 63 (81%) patients; 51 (81%) noticed a decrease in attack frequency (27 no attacks) and 12 (19%) an increase. Pain intensity change was reported by 18 (35%) patients (50% increase, 50% decrease). Aura symptomatology improved in 4 (11%). Reduced attack frequency was not related to posterior stroke (OR = 1.5, 95% CI: 0.6-3.9), or preventive medication (antiplatelets OR = 1.0, 95% CI: 0.2-3.7; coumarin OR = 2.7, 95% CI: 0.4-20.6). CONCLUSIONS: Most patients with active pre-stroke migraine experience improvement of their symptoms in the first year after ischemic stroke. This change does not seem to be related to secondary stroke preventive medication or posterior stroke location.

Safety considerations in the treatment with anti-CGRP(R) monoclonal antibodies in patients with migraine.

Background: Anti-CGRP-(receptor-)monoclonal antibodies (anti-CGRP(R)-mAbs) represent a novel class of drugs for migraine treatment, but their long-term cerebrovascular and cardiovascular (CV) safety warrants further examination. Methods: In this observational cohort study we assessed the CV safety for erenumab and fremanezumab in a real-world setting during a follow-up period of at least 1 year. Patients with hypertension or CV history were excluded. We conducted ECGs and collected clinical data at treatment initiation and thereafter every 3 months, including liver and kidney function, lipid-, electrolyte-and glucose levels. Results: Among patients receiving erenumab (n = 101) or fremanezumab (n = 92), 3.1% (6/193) developed abnormal ECGs or CV adverse events. Of these, three (1.6%) experienced moderate to severe CV adverse events (cerebellar stroke, spontaneous coronary artery dissection, and pericarditis) and discontinued treatment. The remaining three (1.6%) developed non-threatening ECG abnormalities without physical complaints. No significant changes were observed in liver and kidney function, lipid-, electrolyte-, or glucose levels. Discussion: We observed CV events in 1.6% of patients with 1.5-year follow-up of anti-CGRP(R)-mAbs treatment. We advise awareness regarding CV events in patients with migraine undergoing CGRP-targeted treatment, not as a confirmation of increased risk but as a proactive measure to address potential multifactorial influences.

Case reports: Could sexual dysfunction in women with migraine be a side effect of CGRP inhibition?

BACKGROUND: The development and approval of antibodies targeting calcitonin gene-related peptide or its receptor mark a revolutionary era for preventive migraine treatment. Real-world evidence sheds light on rare, stigmatized or overlooked side effects of these drugs. One of these potential side effects is sexual dysfunction. CASE REPORTS: We present two cases of one 42-year-old and one 45-year-old female patient with chronic migraine who both reported sexual dysfunction as a possible side effect of treatment with galcanezumab, a monoclonal antibody targeting calcitonin gene-related peptide. DISCUSSION: As calcitonin gene-related peptide is involved in vaginal lubrication as well as genital sensation and swelling, inhibiting the calcitonin gene-related peptide pathway may lead to sexual dysfunction as a potential side effect. CONCLUSION: Sexual dysfunction in female migraine patients might be a rare and overlooked side effect of monoclonal antibodies targeting the calcitonin gene-related peptide pathway. Considering the discomfort and stigma surrounding both migraine and sexual dysfunction, we advocate for an open attitude and awareness among clinicians toward such side effects.

Intracellular pathways of calcitonin gene-related peptide-induced relaxation of human coronary arteries: A key role for Gßγ subunit instead of cAMP.

BACKGROUND AND PURPOSE: Calcitonin gene-related peptide (CGRP) is a potent vasodilator. While its signalling is assumed to be mediated via increases in cAMP, this study focused on elucidating the actual intracellular signalling pathways involved in CGRP-induced relaxation of human isolated coronary arteries (HCA). EXPERIMENTAL APPROACH: HCA were obtained from heart valve donors (27 M, 25 F, age 54 ± 2 years). Concentration-response curves to human α-CGRP or forskolin were constructed in HCA segments, incubated with different inhibitors of intracellular signalling pathways, and intracellular cAMP levels were measured with and without stimulation. RESULTS: Adenylyl cyclase (AC) inhibitors SQ22536 + DDA and MDL-12330A, and PKA inhibitors Rp-8-Br-cAMPs and H89, did not inhibit CGRP-induced relaxation of HCA, nor did the guanylyl cyclase inhibitor ODQ, PKG inhibitor KT5823, EPAC1/2 inhibitor ESI09, potassium channel blockers TRAM-34 + apamin, iberiotoxin or glibenclamide, or the Gαq inhibitor YM-254890. Phosphodiesterase inhibitors induced a concentration-dependent decrease in the response to KCl but did not potentiate relaxation to CGRP. Relaxation to forskolin was not blocked by PKA or AC inhibitors, although AC inhibitors significantly inhibited the increase in cAMP. Inhibition of Gßγ subunits using gallein significantly inhibited the relaxation to CGRP in human coronary arteries. CONCLUSION: While CGRP signalling is generally assumed to act via cAMP, the CGRP-induced vasodilation in HCA was not inhibited by targeting this intracellular signalling pathway at different levels. Instead, inhibition of Gßγ subunits did inhibit the relaxation to CGRP, suggesting a different mechanism of CGRP-induced relaxation than generally believed.

Pharmacology of erenumab in human isolated coronary and meningeal arteries: Additional effect of gepants on top of a maximum effect of erenumab.

BACKGROUND AND PURPOSE: Multiple drugs targeting the calcitonin gene-related peptide (CGRP) receptor have been developed for migraine treatment. Here, the effect of the monoclonal antibody erenumab on CGRP-induced vasorelaxation was investigated in human isolated blood vessels, as well as the effect of combining erenumab with the small molecule drugs, namely rimegepant, olcegepant, or sumatriptan. EXPERIMENTAL APPROACH: Concentration-response curves to CGRP, adrenomedullin or pramlintide were constructed in human coronary artery (HCA) and human middle meningeal artery (HMMA) segments, incubated with or without erenumab and/or olcegepant. pA2 or pKb values were calculated to determine the potency of erenumab in both tissues. To study whether acutely acting antimigraine drugs exerted additional CGRP-blocking effects on top of erenumab, HCA segments were incubated with a maximally effective concentration of erenumab (3 µM), precontracted with KCl and exposed to CGRP, followed by rimegepant, olcegepant, or sumatriptan in increasing concentrations. KEY RESULTS: Erenumab shifted the concentration-response curve to CGRP in both vascular tissues. However, in HCA, the Schild plot slope was significantly smaller than unity, whereas this was not the case in HMMA, indicating different CGRP receptor mechanisms in these tissues. In HCA, rimegepant, olcegepant and sumatriptan exerted additional effects on CGRP on top of a maximal effect of erenumab. CONCLUSIONS AND IMPLICATIONS: Gepants have additional effects on top of erenumab for CGRP-induced relaxation and could be effective in treating migraine attacks in patients already using erenumab as prophylaxis.

Functional Analysis of TRPA1, TRPM3, and TRPV1 Channels in Human Dermal Arteries and Their Role in Vascular Modulation.

Transient receptor potential (TRP) channels are pivotal in modulating vascular functions. In fact, topical application of cinnamaldehyde or capsaicin (TRPA1 and TRPV1 channel agonists, respectively) induces "local" changes in blood flow by releasing vasodilator neuropeptides. We investigated TRP channels' contributions and the pharmacological mechanisms driving vasodilation in human isolated dermal arteries. Ex vivo studies assessed the vascular function of artery segments and analyzed the effects of different compounds. Concentration-response curves to cinnamaldehyde, pregnenolone sulfate (PregS, TRPM3 agonist), and capsaicin were constructed to evaluate the effect of the antagonists HC030031 (TRPA1); isosakuranetin (TRPM3); and capsazepine (TRPV1). Additionally, the antagonists/inhibitors olcegepant (CGRP receptor); L-NAME (nitric oxide synthase); indomethacin (cyclooxygenase); TRAM-34 plus apamin (K+ channels); and MK-801 (NMDA receptors, only for PregS) were used. Moreover, CGRP release was assessed in the organ bath fluid post-agonist-exposure. In dermal arteries, cinnamaldehyde- and capsaicin-induced relaxation remained unchanged after the aforementioned antagonists, while PregS-induced relaxation was significantly inhibited by isosakuranetin, L-NAME and MK-801. Furthermore, there was a significant increase in CGRP levels post-agonist-exposure. In our experimental model, TRPA1 and TRPV1 channels seem not to be involved in cinnamaldehyde- or capsaicin-induced relaxation, respectively, whereas TRPM3 channels contribute to PregS-induced relaxation, possibly via CGRP-independent mechanisms.

Continuous combined oral contraceptive use versus vitamin E in the treatment of menstrual migraine: rationale and protocol of a randomized controlled trial (WHAT!).

BACKGROUND: Currently, there is no evidence-based hormonal treatment for migraine in women. Several small studies suggest a beneficial effect of combined oral contraceptives, but no large randomized controlled trial has been performed. As proof of efficacy is lacking and usage may be accompanied by potentially severe side effects, there is a great need for clarity on this topic. METHODS: Women with menstrual migraine (n = 180) are randomly assigned (1:1) to ethinylestradiol/levonorgestrel 30/150 µg or vitamin E 400 IU. Participants start with a baseline period of 4 weeks, which is followed by a 12-week treatment period. During the study period, a E-headache diary will be used, which is time-locked and includes an automated algorithm differentiating headache and migraine days. RESULTS: The primary outcome will be change in monthly migraine days (MMD) from baseline (weeks - 4 to 0) to the last 4 weeks of treatment (weeks 9 to 12). Secondary outcomes will be change in monthly headache days (MHD) and 50% responder rates of MMD and MHD. CONCLUSIONS: The WHAT! trial aims to investigate effectivity and safety of continuous combined oral contraceptive treatment for menstrual migraine. Immediate implementation of results in clinical practice is possible. TRIAL REGISTRATION: Clinical trials.gov NCT04007874 . Registered 28 June 2019.

Depression and treatment with anti-calcitonin gene related peptide (CGRP) (ligand or receptor) antibodies for migraine.

BACKGROUND AND PURPOSE: The aim was to evaluate the effect of anti-calcitonin gene related peptide (CGRP) (ligand or receptor) antibodies on depressive symptoms in subjects with migraine and to determine whether depressive symptoms predict treatment response. METHODS: Patients with migraine treated with erenumab and fremanezumab at the Leiden Headache Centre completed daily E-headache diaries. A control group was included. Depressive symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS) and the Center for Epidemiological Studies Depression Scale (CES-D) questionnaires at baseline (T0) and after 3 months (T1). First, the effect of treatment on the reduction in HADS-D and CES-D scores was assessed, with reduction in depression scores as the dependent variable and reduction in monthly migraine days (MMD) and treatment with anti-CGRP medication as independent variables. Second, depression as a predictor of treatment response was investigated, using the absolute reduction in MMD as a dependent variable and age, gender, MMD, active depression, impact, stress and locus of control scores as independent variables. RESULTS: In total, n = 108 patients were treated with erenumab, n = 90 with fremanezumab and n = 68 were without active treatment. Treatment with anti-CGRP medication was positively associated with a reduction in the HADS-D (ß = 1.65, p = 0.01) compared to control, independent of MMD reduction. However, the same effect was not found for the CES-D (ß = 2.15, p = 0.21). Active depression predicted poorer response to erenumab (p = 0.02) but not to fremanezumab (p = 0.09). CONCLUSION: Anti-CGRP (ligand or receptor) monoclonals lead to improvement of depressive symptoms in individuals with migraine, independent of migraine reduction. Depression may predict treatment response to erenumab but not to fremanezumab.

Considerations for hormonal therapy in migraine patients: a critical review of current practice.

INTRODUCTION: Migraine, a neurovascular headache disorder, is a leading cause of disability worldwide. Within the multifaceted pathophysiology of migraine, hormonal fluctuations play an evident triggering and exacerbating role, pointing toward the need for identification and proper usage of both existing and new hormonal targets in migraine treatment. AREAS COVERED: With a threefold higher incidence of migraine in women than in men, the authors delve into sex hormone-related events in migraine patients. A comprehensive overview is given of existing hormonal therapies, including oral contraceptives, intrauterine devices, transdermal and subcutaneous estradiol patches, gnRH-agonists, oral testosterone, and 5α reductase inhibitors. The authors discuss their effectiveness and risks, noting their suitability for different patient profiles. Next, novel evolving hormonal treatments, such as oxytocin and prolactin, are explored. Lastly, the authors cover hormonal conditions associated with migraine, such as polycystic ovary syndrome, endometriosis, and transgender persons receiving gender affirming hormone therapy, aiming to provide more personalized and effective solutions for migraine management. EXPERT OPINION: Rigorous research into both existing and new hormonal targets, as well as the underlying pathophysiology, is needed to support a tailored approach in migraine treatment, in an ongoing effort to alleviate the impact of migraine on individuals and society.

Pharmacological Nature of the Purinergic P2Y Receptor Subtypes That Participate in the Blood Pressure Changes Produced by ADPßS in Rats.

Purine nucleosides (adenosine) and nucleotides such as adenosine mono/di/triphosphate (AMP/ADP/ATP) may produce complex cardiovascular responses. For example, adenosine-5'-(ß-thio)-diphosphate (ADPßS; a stable synthetic analogue of ADP) can induce vasodilatation/vasodepressor responses by endothelium-dependent and independent mechanisms involving purinergic P2Y receptors; however, the specific subtypes participating in these responses remain unknown. Therefore, this study investigated the receptor subtypes mediating the blood pressure changes induced by intravenous bolus of ADPßS in male Wistar rats in the absence and presence of central mechanisms with the antagonists MRS2500 (P2Y1), PSB0739 (P2Y12), and MRS2211 (P2Y13). For this purpose, 120 rats were divided into 60 anaesthetised rats and 60 pithed rats, and further subdivided into four groups (n = 30 each), namely: (a) anaesthetised rats, (b) anaesthetised rats with bilateral vagotomy, (c) pithed rats, and (d) pithed rats continuously infused (intravenously) with methoxamine (an α1-adrenergic agonist that restores systemic vascular tone). We observed, in all four groups, that the immediate decreases in diastolic blood pressure produced by ADPßS were exclusively mediated by peripheral activation of P2Y1 receptors. Nevertheless, the subsequent increases in systolic blood pressure elicited by ADPßS in pithed rats infused with methoxamine probably involved peripheral activation of P2Y1, P2Y12, and P2Y13 receptors.

Rethinking headache as a global public health case model for reaching the SDG 3 HEALTH by 2030.

The 2030 Agenda for Sustainable Development sets out, through 17 Sustainable Development Goals (SDGs), a path for the prosperity of people and the planet. SDG 3 in particular aims to ensure healthy lives and promote well-being for all at all ages and includes several targets to enhance health. This review presents a "headache-tailored" perspective on how to achieve SDG 3 by focusing on six specific actions: targeting chronic headaches; reducing the overuse of acute pain-relieving medications; promoting the education of healthcare professionals; granting access to medication in low- and middle-income countries (LMIC); implementing training and educational opportunities for healthcare professionals in low and middle income countries; building a global alliance against headache disorders. Addressing the burden of headache disorders directly impacts on populations' health, as well as on the possibility to improve the productivity of people aged below 50, women in particular. Our analysis pointed out several elements, and included: moving forward from frequency-based parameters to define headache severity; recognizing and managing comorbid diseases and risk factors; implementing a disease management multi-modal management model that incorporates pharmacological and non-pharmacological treatments; early recognizing and managing the overuse of acute pain-relieving medications; promoting undergraduate, postgraduate, and continuing medical education of healthcare professionals with specific training on headache; and promoting a culture that favors the recognition of headaches as diseases with a neurobiological basis, where this is not yet recognized. Making headache care more sustainable is an achievable objective, which will require multi-stakeholder collaborations across all sectors of society, both health-related and not health-related. Robust investments will be needed; however, considering the high prevalence of headache disorders and the associated disability, these investments will surely improve multiple health outcomes and lift development and well-being globally.

European Headache Federation (EHF) critical reappraisal and meta-analysis of oral drugs in migraine prevention - part 3: topiramate.

OBJECTIVE: Topiramate is a repurposed first-line treatment for migraine prophylaxis. The aim of this systematic review and meta-analysis is to critically re-appraise the existing evidence supporting the efficacy and tolerability of topiramate. METHODS: A systematic search in MEDLINE, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov was performed for trials of pharmacological treatment in migraine prophylaxis as of August 13, 2022, following the Preferred Reporting Items for Systematic Reviews (PRISMA). Randomized controlled trials in adult patients that used topiramate for the prophylactic treatment of migraine, with placebo as active comparator, were included. Two reviewers independently screened the retrieved studies and extracted all data. Outcomes of interest were the 50% responder rates, the reduction in monthly migraine days, and adverse events leading to treatment discontinuation. Results were pooled and meta-analyzed, with sensitivity analysis based on the risk of bias of the studies, the monthly migraine days at baseline, and the previous use of other prophylactic treatments. Certainty evidence was judged according to the GRADE framework. RESULTS: Eight out of 10,826 studies fulfilled the inclusion/exclusion criteria, accounting for 2,610 randomized patients. Six studies included patients with episodic migraine and two with chronic migraine. Topiramate dose ranged from 50 to 200 mg/day, and all studies included a placebo arm. There was a high certainty that topiramate: 1) increased the proportion of patients who achieved a 50% responder rate in monthly migraine days, compared to placebo [relative risk: 1.61 (95% confidence interval (CI): 1.29-2.01); absolute risk difference: 168 more per 1,000 (95% CI: 80 to 278 more)]; 2) was associated with 0.99 (95% CI: 1.41-0.58) fewer migraine days than placebo; 3) and had a higher proportion of patients with adverse events leading to treatment discontinuation [absolute risk difference 80 patients more per 1,000 (95% CI: 20 to 140 more patients)]. CONCLUSIONS: There is high-quality evidence of the efficacy of topiramate in the prophylaxis of migraine, albeit its use poses a risk of adverse events that may lead to treatment discontinuation, with a negative effect on patient satisfaction and adherence to care.

European Headache Federation (EHF) critical re-appraisal and meta-analysis of oral drugs in migraine prevention-part 2: flunarizine.

OBJECTIVE: Novel disease-specific and mechanism-based treatments sharing good evidence of efficacy for migraine have been recently marketed. However, reimbursement by insurers depends on treatment failure with classic anti-migraine drugs. In this systematic review and meta-analysis, we aimed to identify and rate the evidence for efficacy of flunarizine, a repurposed, first- or second-line treatment for migraine prophylaxis. METHODS: A systematic search in MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov was performed for trials of pharmacological treatment in migraine prophylaxis, following the Preferred Reporting Items for Systematic Reviews (PRISMA). Eligible trials for meta-analysis were randomized, placebo-controlled studies comparing flunarizine with placebo. Outcomes of interest according to the Outcome Set for preventive intervention trials in chronic and episodic migraine (COSMIG) were the proportion of patients reaching a 50% or more reduction in monthly migraine days, the change in monthly migraine days (MMDs), and Adverse Events (AEs) leading to discontinuation. RESULTS: Five trials were eligible for narrative description and three for data synthesis and analysis. No studies reported the predefined outcomes, but one study assessed the 50% reduction in monthly migraine attacks with flunarizine as compared to placebo showing a benefit from flunarizine with a low or probably low risk of bias. We found that flunarizine may increase the proportion of patients who discontinue due to adverse events compared to placebo (risk difference: 0.02; 95% CI -0.03 to 0.06). CONCLUSIONS: Published flunarizine trials predate the recommended endpoints for evaluating migraine prophylaxis drugs, hence the lack of an adequate assessment for these endpoints. Further, modern-day, large-scale studies would be valuable in re-evaluating the efficacy of flunarizine for the treatment of migraines, offering additional insights into its potential benefits.

Blocking the CGRP Receptor: Differences across Human Vascular Beds.

Multiple drugs targeting the calcitonin gene-related peptide (CGRP) receptor have been developed for the treatment of migraine. Here, the effect of the small-molecule CGRP receptor antagonist zavegepant (0.1 nM-1 µM) on CGRP-induced relaxation in isolated human coronary arteries (HCAs) was investigated. A Schild plot was constructed and a pA2 value was calculated to determine the potency of zavegepant. The potency and Schild plot slopes of atogepant, olcegepant, rimegepant, telcagepant, ubrogepant and zavegepant in HCAs and human middle meningeal arteries (HMMAs), obtained from our earlier studies, were compared. Zavegepant shifted the concentration-response curve to CGRP in HCAs. The corresponding Schild plot slope was not different from unity, resulting in a pA2 value of 9.92 ± 0.24. No potency difference between HCAs and HMMAs was observed. Interestingly, olcegepant, atogepant and rimegepant, with a Schild plot slope < 1 in HCAs, were all >1 log unit more potent in HMMAs than in HCAs, while telcagepant, ubrogepant and zavegepant, with a Schild plot slope not different from unity, showed similar (<1 log difference) potency across both tissues. As a Schild plot slope < 1 may point to the involvement of multiple receptors, it is important to further identify the receptors involved in the relaxation to CGRP in HCAs, which may be used to improve the cardiovascular safety of future antimigraine drugs.

Serotonergic Modulation of Neurovascular Transmission: A Focus on Prejunctional 5-HT Receptors/Mechanisms.

5-Hydroxytryptamine (5-HT), or serotonin, plays a crucial role as a neuromodulator and/or neurotransmitter of several nervous system functions. Its actions are complex, and depend on multiple factors, including the type of effector or receptor activated. Briefly, 5-HT can activate: (i) metabotropic (G-protein-coupled) receptors to promote inhibition (5-HT1, 5-HT5) or activation (5-HT4, 5-HT6, 5-HT7) of adenylate cyclase, as well as activation (5-HT2) of phospholipase C; and (ii) ionotropic receptor (5-HT3), a ligand-gated Na+/K+ channel. Regarding blood pressure regulation (and beyond the intricacy of central 5-HT effects), this monoamine also exerts direct postjunctional (on vascular smooth muscle and endothelium) or indirect prejunctional (on autonomic and sensory perivascular nerves) effects. At the prejunctional level, 5-HT can facilitate or preclude the release of autonomic (e.g., noradrenaline and acetylcholine) or sensory (e.g., calcitonin gene-related peptide) neurotransmitters facilitating hypertensive or hypotensive effects. Hence, we cannot formulate a specific impact of 5-HT on blood pressure level, since an increase or decrease in neurotransmitter release would be favoured, depending on the type of prejunctional receptor involved. This review summarizes and discusses the current knowledge on the prejunctional mechanisms involved in blood pressure regulation by 5-HT and its impact on some vascular-related diseases.

Visual hypersensitivity in patients treated with anti-calcitonin gene-related peptide (receptor) monoclonal antibodies.

OBJECTIVE: To evaluate the effect of treatment with anti-calcitonin gene-related peptide (CGRP; receptor) antibodies on visual hypersensitivity in patients with migraine. BACKGROUND: Increased visual sensitivity can be present both during and outside migraine attacks. CGRP has been demonstrated to play a key role in light-aversive behavior. METHODS: In this prospective follow-up study, patients treated for migraine with erenumab (n = 105) or fremanezumab (n = 100) in the Leiden Headache Center were invited to complete a questionnaire on visual sensitivity (the Leiden Visual Sensitivity Scale [L-VISS]), pertaining to both their ictal and interictal state, before starting treatment (T0) and 3 months after treatment initiation (T1). Using a daily e-diary, treatment effectiveness was assessed in weeks 9-12 compared to a 4-week pre-treatment baseline period. L-VISS scores were compared between T0 and T1. Subsequently, the association between the reduction in L-VISS scores and the reduction in monthly migraine days (MMD) was investigated. RESULTS: At 3 months, the visual hypersensitivity decreased, with a decrease in mean ± standard deviation (SD) ictal L-VISS (from 20.1 ± 7.7 to 19.2 ± 8.1, p = 0.042) and a decrease in mean ± SD interictal L-VISS (from 11.8 ± 6.6 to 11.1 ± 7.0, p = 0.050). We found a positive association between the reduction in MMD and the decrease in interictal L-VISS (ß = 0.2, p = 0.010) and the reduction in ictal L-VISS (ß = 0.3, p = 0.001). CONCLUSION: A decrease in visual hypersensitivity in patients with migraine after treatment with anti-CGRP (receptor) antibodies is positively associated with clinical response on migraine.