Environmental enrichment alleviates hyperalgesia by modulating central sensitization in a nitroglycerin-induced chronic migraine model of mice.

BACKGROUND: Chronic migraine (CM) is a debilitating neurofunctional disorder primarily affecting females, characterized by central sensitization. Central sensitization refers to the enhanced response to sensory stimulation, which involves changes in neuronal excitability, synaptic plasticity, and neurotransmitter release. Environmental enrichment (EE) can increase the movement, exploration, socialization and other behaviors of mice. EE has shown promising effects in various neurological disorders, but its impact on CM and the underlying mechanism remains poorly understood. Therefore, the purpose of this study was to determine whether EE has the potential to serve as a cost-effective intervention strategy for CM. METHODS: A mouse CM model was successfully established by repeated administration of nitroglycerin (NTG). We selected adult female mice around 8 weeks old, exposed them to EE for 2 months, and then induced the CM model. Nociceptive threshold tests were measured using Von Frey filaments and a hot plate. The expression of c-Fos, calcitonin gene-related peptide (CGRP) and inflammatory response were measured using WB and immunofluorescence to evaluate central sensitization. RNA sequencing was used to find differentially expressed genes and signaling pathways. Finally, the expression of the target differential gene was investigated. RESULTS: Repeated administration of NTG can induce hyperalgesia in female mice and increase the expression of c-Fos and CGRP in the trigeminal nucleus caudalis (TNC). Early exposure of mice to EE reduced NTG-induced hyperalgesia in CM mice. WB and immunofluorescence revealed that EE inhibited the overexpression of c-Fos and CGRP in the TNC of CM mice and alleviated the inflammatory response of microglia activation. RNA sequencing analysis identified that several central sensitization-related signaling pathways were altered by EE. VGluT1, a key gene involved in behavior, internal stimulus response, and ion channel activity, was found to be downregulated in mice exposed to EE. CONCLUSION: EE can significantly ameliorate hyperalgesia in the NTG-induced CM model. The mechanisms may be to modulate central sensitization by reducing the expression of CGRP, attenuating the inflammatory response, and downregulating the expression of VGluT1, etc., suggesting that EE can serve as an effective preventive strategy for CM.

Extrasynaptic δGABAA receptors mediate resistance to migraine-like phenotype in rats.

BACKGROUND: GABA, a key inhibitory neurotransmitter, has synaptic and extrasynaptic receptors on the postsynaptic neuron. Background GABA, which spills over from the synaptic cleft, acts on extrasynaptic delta subunit containing GABAA receptors. The role of extrasynaptic GABAergic input in migraine is unknown. We investigated the susceptibility to valid migraine-provoking substances with clinically relevant behavioral readouts in Genetic Absence Epilepsy of Rats Strasbourg (GAERS), in which the GABAergic tonus was altered. Subsequently, we screened relevant GABAergic mechanisms in Wistar rats by pharmacological means to identify the mechanisms. METHODS: Wistar and GAERS rats were administered nitroglycerin (10 mg/kg) or levcromakalim (1 mg/kg). Mechanical allodynia and photophobia were assessed using von Frey monofilaments and a dark-light box. Effects of GAT-1 blocker tiagabine (5 mg/kg), GABAB receptor agonist baclofen (2 mg/kg), synaptic GABAA receptor agonist diazepam (1 mg/kg), extrasynaptic GABAA receptor agonists gaboxadol (4 mg/kg), and muscimol (0.75 mg/kg), T-type calcium channel blocker ethosuximide (100 mg/kg) or synaptic GABAA receptor antagonist flumazenil (15 mg/kg) on levcromakalim-induced migraine phenotype were screened. RESULTS: Unlike Wistar rats, GAERS exhibited no reduction in mechanical pain thresholds or light aversion following nitroglycerin or levcromakalim injection. Ethosuximide did not reverse the resistant phenotype in GAERS, excluding the role of T-type calcium channel dysfunction in this phenomenon. Tiagabine prevented levcromakalim-induced mechanical allodynia in Wistar rats, suggesting a key role in enhanced GABA spillover. Baclofen did not alleviate mechanical allodynia. Diazepam failed to mitigate levcromakalim-induced migraine phenotype. Additionally, the resistant phenotype in GAERS was not affected by flumazenil. Extrasynaptic GABAA receptor agonists gaboxadol and muscimol inhibited periorbital allodynia in Wistar rats. CONCLUSION: Our study introduced a rat strain resistant to migraine-provoking agents and signified a critical involvement of extrasynaptic δGABAergic receptors. Extrasynaptic δ GABAA receptors, by mediating constant background inhibition on the excitability of neurons, stand as a novel drug target with a therapeutic potential in migraine.

Effects of the Dual FAAH/MAGL Inhibitor AKU-005 on Trigeminal Hyperalgesia in Male Rats.

The inhibition of endocannabinoid hydrolysis by enzymatic inhibitors may interfere with mechanisms underlying migraine-related pain. The dual FAAH/MAGL inhibitor AKU-005 shows potent inhibitory activity in vitro. Here, we assessed the effect of AKU-005 in a migraine animal model based on nitroglycerin (NTG) administration. Male rats were treated with AKU-005 (0.5 mg/kg, i.p.) or vehicle 3 h after receiving NTG (10 mg/kg, i.p.) or NTG vehicle. One hour later, rats were subjected to the open field test followed by the orofacial formalin test. At the end of the test, we collected serum samples for assessing calcitonin gene-related peptide (CGRP) levels as well as meninges, trigeminal ganglia, and brain areas to assess mRNA levels of CGRP and pro-inflammatory cytokines, and endocannabinoid and related lipid levels. AKU-005 reduced NTG-induced hyperalgesia during the orofacial formalin test but did not influence NTG-induced changes in the open field test. It significantly reduced serum levels of CGRP, CGRP, and pro-inflammatory cytokine mRNA levels in the meninges, trigeminal ganglia, and central areas. Surprisingly, AKU-005 caused no change in endocannabinoids and related lipids in the regions evaluated. The present findings suggest that AKU-005 may have anti-migraine effects by reducing CGRP synthesis and release and the associated inflammatory events. This effect, however, does not seem mediated via an interference with the endocannabinoid pathway.

Effectiveness and Safety of OnabotulinumtoxinA in Adolescent Patients with Chronic Migraine.

Chronic migraine (CM) significantly affects underage individuals. The study objectives are (1) to analyze the effectiveness and safety of onabotulinumtoxinA (BTX-A) in adolescents with CM; (2) to review the literature on BTX-A use in the pediatric population. This prospective observational study included patients under 18 years old with CM treated with BTX-A (PREEMPT protocol) as compassionate use. Demographic, efficacy (monthly headache days-MHD; monthly migraine days-MMD; acute medication days/month-AMDM) and side effect data were collected. A ≥ 50% reduction in MHD was considered as a response. Effectiveness and safety were analyzed at 6 and 12 months. A systematic review of the use of BTX-A in children/adolescents was conducted in July 2023. In total, 20 patients were included (median age 15 years [14.75-17], 70% (14/20) females). The median basal frequencies were 28.8 [20-28] MHD, 18 [10-28] MMD and 10 [7.5-21.2] AMDM. Compared with baseline, at 6 months (n = 20), 11 patients (55%) were responders, with a median reduction in MHD of -20 days/month (p = 0.001). At 12 months (n = 14), eight patients (57.1%) were responders, with a median reduction in MHD of -17.5 days/month (p = 0.002). No adverse effects were reported. The literature search showed similar results. Our data supports the concept that BTX-A is effective, well tolerated, and safe in adolescents with CM resistant to oral preventatives.

MicroRNA profiling in women with migraine: effects of CGRP-targeting treatment.

BACKGROUND: Migraine lacks biomarkers that can trace the biological pathways of the disease and predict the effectiveness of treatments. Monoclonal antibodies targeting calcitonin gene-related peptide pathway - including erenumab - offer the opportunity of investigating potential migraine biomarkers due to their specific mechanism of action in preventing both episodic (EM) and chronic (CM) migraine. Our study aims at evaluating the expression levels of circulating microRNAs (miRNAs) according to migraine type, before and after treatment with erenumab and based on treatment response, in order to identify miRNAs with potential role as epigenetic biomarkers. METHODS: The study included women aged 25-50 years with EM or CM treated with erenumab according to clinical indications. MiRNAs expression levels were assessed before (baseline) and after a 16-week treatment with erenumab, 140 mg every four weeks (post-treatment). An extensive miRNAs profiling was performed by qRT-PCR in small, pooled groups of ≤ 8 women each, classified according to migraine frequency (EM and CM) and the degree of response to erenumab. The expression levels of selected miRNAs were also validated using single miRNA assays in each woman with EM and CM. RESULTS: During the study, 36 women with migraine (19 with EM and 17 with CM) out of 40 who were initially screened, performed the assessment of miRNA expression at baseline and post-treatment, Erenumab treatment significantly improved migraine burden in both EM and CM. MiRNA profiling revealed differential expression levels of a wide set of miRNAs (hsa-let-7d-3p, hsa-miR-106b-3p, hsa-miR-122-5p, hsa-miR-143-3p, hsa-miR-144-3p, hsa-miR-16-5p, hsa-miR-181a-5p, hsa-miR-221-3p, hsa-miR-25-3p, hsa-miR-29b-2-5p, hsa-miR-326, miR-363-3p, hsa-miR-424-5p, hsa-miR-485-3p, hsa-miR-532-5p, hsa-miR-543, hsa-miR-629-5p, hsa-miR-660-5p, hsa-miR-92a-3p) depending on treatment response. Among them, single miRNA assays confirmed the progressive decrease of hsa-miR-143-3p expression levels in relation to increasing response to erenumab in women with EM (7 with low, 6 with medium, and 6 with high response; p = 0.02). Additionally, single assays showed higher hsa-miR-34a-5p and hsa-miR-382-5p expression levels at baseline in women with CM compared with those with EM (p = 0.0002 and p = 0.0007, respectively), as well as their expression level decrease in women with CM from baseline to follow-up (p = 0.04 and p = 0.02, respectively). CONCLUSIONS: Our study suggests that targeting the CGRP pathway in migraine changes the expression levels of certain miRNAs. These miRNA levels are linked to the levels of response to CGRP receptor blockage. Future research challenges include assigning specific functions to the modulated miRNAs to unravel pathways modulated by the disease and the treatment. TRIAL REGISTRATION: The study was registered in clinicaltrials.gov with code NCT04659226 and in the Novartis database with code CAMG334AIT05T.

Alleviation of migraine related pain and anxiety by inhibiting calcium-stimulating AC1-dependent CGRP in the insula of adult rats.

BACKGROUND: Recent animal and clinical findings consistently highlight the critical role of calcitonin gene-related peptide (CGRP) in chronic migraine (CM) and related emotional responses. CGRP antibodies and receptor antagonists have been approved for CM treatment. However, the underlying CGRP-related signaling pathways in the pain-related cortex remain poorly understood. METHODS: The SD rats were used to establish the CM model by dural infusions of inflammatory soup. Periorbital mechanical thresholds were assessed using von-Frey filaments, and anxiety-like behaviors were observed via open field and elevated plus maze tests. Expression of c-Fos, CGRP and NMDA GluN2B receptors was detected using immunofluorescence and western blotting analyses. The excitatory synaptic transmission was detected by whole-cell patch-clamp recording. A human-used adenylate cyclase 1 (AC1) inhibitor, hNB001, was applied via insula stereotaxic and intraperitoneal injections in CM rats. RESULTS: The insular cortex (IC) was activated in the migraine model rats. Glutamate-mediated excitatory transmission and NMDA GluN2B receptors in the IC were potentiated. CGRP levels in the IC significantly increased during nociceptive and anxiety-like activities. Locally applied hNB001 in the IC or intraperitoneally alleviated periorbital mechanical thresholds and anxiety behaviors in migraine rats. Furthermore, CGRP expression in the IC decreased after the hNB001 application. CONCLUSIONS: Our study indicated that AC1-dependent IC plasticity contributes to migraine and AC1 may be a promising target for treating migraine in the future.

Implications of high homocysteine levels in migraine pain: An experimental study of the excitability of peripheral meningeal afferents in rats with hyperhomocysteinemia.

OBJECTIVES: Investigation of chronic homocysteine action on the excitability and N-methyl-D-aspartate (NMDA) sensitivity of the peripheral trigeminovascular system of rats. BACKGROUND: Migraine is a neurological disease that affects 15%-20% of the general population. Epidemiological observations show that an increase of the sulfur-containing amino acid homocysteine in plasma-called hyperhomocysteinemia-is associated with a high risk of migraine, especially migraine with aura. In animal studies, rats with hyperhomocysteinemia demonstrated mechanical allodynia, photophobia, and anxiety, and higher sensitivity to cortical spreading depression. In addition, rats with hyperhomocysteinemia were more sensitive in a model of chronic migraine induced by nitroglycerin which indicated the involvement of peripheral nociceptive mechanisms. The present work aimed to analyze the excitability of meningeal afferents and neurons isolated from the trigeminal ganglion of rats with prenatal hyperhomocysteinemia. METHODS: Experiments were performed on male rats born from females fed with a methionine-rich diet before and during pregnancy. The activity of meningeal afferents was recorded extracellularly in hemiskull preparations ex vivo and action potentials were characterized using cluster analysis. The excitability of trigeminal ganglion neurons was assessed using whole-cell patch clamp recording techniques and calcium imaging studies. Meningeal mast cells were stained using toluidine blue. RESULTS: The baseline extracellular recorded electrical activity of the trigeminal nerve was higher in the hyperhomocysteinemia group with larger amplitude action potentials. Lower concentrations of KCl caused an increase in the frequency of action potentials of trigeminal afferents recorded in rat hemiskull ex vivo preparations. In trigeminal ganglion neurons of rats with hyperhomocysteinemia, the current required to elicit at least one action potential (rheobase) was lower, and more action potentials were induced in response to stimulus of 2 × rheobase. In controls, short-term application of homocysteine and its derivatives increased the frequency of action potentials of the trigeminal nerve and induced Ca2+ transients in neurons, which are associated with the activation of NMDA receptors. At the same time, in rats with hyperhomocysteinemia, we did not observe an increased response of the trigeminal nerve to NMDA. Similarly, the parameters of Ca2+ transients induced by NMDA, homocysteine, and its derivatives were not changed in rats with hyperhomocysteinemia. Acute incubation of the meninges in homocysteine and homocysteinic acid did not change the state of the mast cells, whereas in the model of hyperhomocysteinemia, an increased degranulation of mast cells in the meninges was observed. CONCLUSIONS: Our results demonstrated higher excitability of the trigeminal system of rats with hyperhomocysteinemia. Together with our previous finding about the lower threshold of generation of cortical spreading depression in rats with hyperhomocysteinemia, the present data provide evidence of homocysteine as a factor that increases the sensitivity of the peripheral migraine mechanisms, and the control of homocysteine level may be an important strategy for reducing the risk and/or severity of migraine headache attacks.

The effect of anesthetic blockade of greater occipital nerve during the withdrawal period of the medication overuse headache treatment.

Background and purpose:

Discontinua­tion of medication still remains a key element in the treatment of medication overuse headache (MOH), but there is no consensus on the withdrawal procedure. We aimed to share the promising results of anesthetic blockade of greater occipital nerve (GON), which can be an alternative to existing treatments during the early withdrawal period of MOH treatment.

This study was conducted using regular electronic medical records and headache diaries of patients diagnosed with MOH and treated with anesthetic GON blockade with 0.5% bupivacaine solution in a specia­lized headache outpatient clinic. A total of 86 patients who developed MOH while being followed up for chronic migraine were included in the study.

The treatment schemes for MOH are based on expert consensus and withdrawal strategies are the most challenging part of treatment. In our study, numerical rating scale for headache intensity, overused medication consumption per month, headache frequency (day/month) and the duration of each attack (hour/day) decreased significantly in the first month compared to pre-treatment (p < 0.01). 

Conclusion – Our study suggests that GON blockade can be used as a good alternative therapy in the treatment of MOH.

Healthcare utilisation and economic burden of migraines among bank employees in China: a probabilistic modelling study.

BACKGROUND: Despite the recognised high prevalence of migraines among bank employees, yet their healthcare utilisation patterns and the economic burden of migraines remain underexplored. AIM: To examine migraine-related healthcare utilisation among bank employees in China, and to estimate the economic burden of migraines. METHODS: A cross-sectional survey was conducted in Guizhou province, China between May and October 2022. The HARDSHIP questionnaire was used to identify migraine-positive individuals and enquire about their healthcare utilisation and productivity losses. A probabilistic decision-analytic model with a micro-costing approach was used to estimate the economic burden from the perspectives of the healthcare system, employers, and society. All costs were expressed in 2022 United States dollars. One-way and probabilistic sensitivity analyses were performed. RESULTS: Nearly half of individuals with migraines reported not seeking medical care. Only 21.8% reported seeking outpatient consultations, 52.5% reported taking medicines, and 27.1% reported using complementary therapies. Chronic migraine patients had significantly higher healthcare utilisation than episodic migraine patients. Among individuals with a monthly migraine frequency of 15 days or more, 63.6% took inappropriate treatments by excessively using acute medications. Migraines in the banking sector in Guizhou cost the healthcare system a median of $7,578.0 thousand (25th to 75th percentile $4,509.2-$16,434.9 thousand) per year, employers $89,750.3 thousand (25th to 75th percentile $53,211.6-$151,162.2 thousand), and society $108,850.3 thousand (25th to 75th percentile $67,370.1-$181,048.6 thousand). The median societal cost per patient-year is $3,078.1. Migraine prevalence and productivity losses were identified as key cost drivers. CONCLUSIONS: The study points to the need to raise awareness of migraines across all stakeholders and to improve the organisation of the migraine care system. A substantial economic burden of migraines on the healthcare system, employers, and society at large was highlighted. These cost estimates offer evidence-based benchmarks for assessing economic savings from improved migraine management, and can also draw the attention of Chinese policymakers to prioritise migraine policies within the banking and other office-based occupations.

Burden of Neurologic Health Care and Incident Neurologic Diagnoses in the Year After COVID-19 or Influenza Hospitalization.

BACKGROUND AND OBJECTIVE: Following the outbreak of viral infections from the severe acute respiratory syndrome coronavirus 2 virus in 2019 (coronavirus disease 2019 [COVID-19]), reports emerged of long-term neurologic sequelae in survivors. To better understand the burden of neurologic health care and incident neurologic diagnoses in the year after COVID-19 vs influenza, we performed an analysis of patient-level data from a large collection of electronic health records (EMR). METHODS: We acquired deidentified data from TriNetX, a global health research network providing access to EMR data. We included individuals aged 18 years or older during index event, defined as hospital-based care for COVID-19 (from April 1, 2020, until November 15, 2021) or influenza (from 2016 to 2019). The study outcomes were subsequent health care encounters over the following year for 6 neurologic diagnoses including migraine, epilepsy, stroke, neuropathy, movement disorders, and dementia. We also created a composite of the 6 diagnoses as an incident event, which we call "incident neurologic diagnoses." We performed a 1:1 complete case nearest-neighbor propensity score match on age, sex, race/ethnicity, marital status, US census region patient residence, preindex years of available data, and Elixhauser comorbidity score. We fit time-to-event models and reported hazard ratios for COVID-19 vs influenza infection. RESULTS: After propensity score matching, we had a balanced cohort of 77,272 individuals with COVID-19 and 77,272 individuals with influenza. The mean age was 51.0 ± 19.7 years, 57.7% were female, and 41.5% were White. Compared with patients with influenza, patients with COVID-19 had a lower risk of subsequent care for migraine (HR 0.645, 95% CI 0.604-0.687), epilepsy (HR 0.783, 95% CI 0.727-0.843), neuropathies (HR 0.567, 95% CI 0.532-0.604), movement disorders (HR 0.644, 95% CI 0.598-0.693), stroke (HR 0.904, 95% CI 0.845-0.967), or dementia (HR 0.931, 95% CI 0.870-0.996). Postinfection incident neurologic diagnoses were observed in 2.79% of the COVID-19 cohort vs 4.91% of the influenza cohort (HR 0.618, 95% CI 0.582-0.657). DISCUSSION: Compared with a matched cohort of adults with a hospitalization or emergency department visit for influenza infection, those with COVID-19 had significantly fewer health care encounters for 6 major neurologic diagnoses over a year of follow-up. Furthermore, we found that COVID-19 infection was associated with a lower risk of an incident neurologic diagnosis in the year after infection.

The effect of selenium supplementation on oxidative stress, clinical symptoms and mental health status in patients with migraine: a study protocol for a double-blinded randomized clinical trial.

BACKGROUND: Despite a number of recommended strategies, effective treatment of migraine remains elusive. Given the role of oxidative stress in the pathogenesis of migraine, selenium, as an antioxidant nutrient, may have a beneficial effect on migraine outcomes. However, no study has explored the effects of selenium supplementation on migraine symptoms, oxidative stress biomarkers, and mental health. Therefore, this randomized, double-blinded, placebo-controlled clinical trial aims to examine the effects of selenium supplementation among migraine patients. METHODS: Seventy-two migraine patients will receive either 200 µg/day selenium supplement (n = 36) or placebo (n = 36) for 12 weeks in a randomized, double-blinded, placebo-controlled study. The severity, frequency, and duration of headaches, mental health indices including depression, anxiety, and distress, and quality of life, as well as biomarkers of oxidative stress such as nitric oxide (NO), malondialdehyde (MDA), total antioxidant capacity (TAC), and total oxidant status (TOS), will be measured at the baseline and end of the study. The intention-to-treat (ITT) approach will be used to estimate missing values. One-way analysis of covariance (ANCOVA) will be performed to detect the effect of selenium supplementation on outcome variables. DISCUSSION: Oxidative stress is recognized as a key contributor to migraine pathogenesis. Selenium is an essential trace element with antioxidant properties, capable of crossing the blood-brain barrier (BBB), holding promise to alleviate the oxidative stress and neurotoxicity. Thus, selenium may beneficially affect clinical symptoms and oxidative stress as well as the quality of life in migraine patients. TRIAL REGISTRATION: This trial was registered in the Iranian Registry of Clinical Trials ( https://www.irct.ir/ ) on 27 May 2023 with the code number IRCT20121216011763N60.

Addressing limitations of single GON blockade treatment and repetitive intervention with GON block or onabotulinum toxin A in chronic migraine- part 2 of three men in a boat study.

This study investigated the effectiveness of three treatment interventions for managing migraine symptoms over a three-month assessment period: single greater occipital nerve block (GON), repetitive GON block, and single GON block combined with onabotulinium toxin A (BoNT-A) treatment. Significant improvements were observed across all treatment groups in various migraine-related parameters, including medication usage, frequency and severity of attacks, and subjective measures such as Headache Impact Test-6 scores and Pittsburgh Sleep Quality Index scores. Notably, all groups showed reductions in NSAID and triptan usage, total number of attacks with VAS>4, and number of headache days. However, slight differences in the magnitude of improvements were observed between the groups, with GON block combined with BoNT-A treatment demonstrating slightly greater reductions compared to single GON block treatment. Additionally, the integration of BoNT-A therapy alongside GON blockade appeared to confer supplementary benefits in migraine prophylaxis. These findings highlight the importance of implementing comprehensive treatment approaches to address various aspects of migraine management and improve patient outcomes.

The Use of Botulinum Toxin Type A in Medically Refractory Pediatric Patients With Chronic Daily Headaches and Its Impact on the Quality of Life.

Background: Chronic migraine in children has been a challenging condition to treat, prompting the investigation of alternative therapies. This retrospective single-center chart review aimed to evaluate the efficacy and safety of Botox injections for managing chronic migraine in children. Methods: The study included children with chronic daily headaches and chronic migraine who were medically refractory to previous treatments at OSF Healthcare/Illinois Neurological Institute, Peoria, between 2015 and 2021. Botox injections were administered quarterly following a specific protocol. Data were obtained from electronic medical records by manual review. Results: Twenty-four patients met the inclusion criteria (median age 15.4 years, 87% female). Comorbidities included depression (41.6%) and sleep disturbances (33.2%). Prior to Botox treatment, patients had been tried on a median number of 5 (interquartile range [IQR] 4, 7) medications. Botox injections resulted in a significant reduction in headache frequency, with a mean difference (6 months vs pretreatment) in the Headache Impact Test (HIT 3) scores of -19.6 (95% CI -24.8, -14.3), P < .001, and mean difference in the Migraine Disability Assessment (MIDAS) scores of -50.8 (95% CI -62.6, -39.0, P < .001). Subjective improvements included mood enhancement (13/24, 54.2%) and improved concentration (12/24, 50%). Treatment-related side effects were reported by 5/24 (20%) of patients and were mostly mild to moderate. Conclusions: Botox injections offer a promising therapeutic option for managing chronic migraine in children who have not responded to traditional medications. Future controlled trials and long-term follow-up studies are needed to further evaluate Botox treatment's benefits and adverse effects in children with chronic migraine.

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.

Amelioration of nitroglycerin-induced migraine in mice via Wuzhuyu decoction: Inhibition of the MZF1/PGK1 pathway and activation of NRF2 antioxidant response.

ETHNOPHARMACOLOGICAL RELEVANCE: Migraine, a chronic and intricate disorder, manifests as recurrent episodic headaches accompanied by various neurological symptoms. Wuzhuyu Decoction (WZYD) is a traditional Chinese medical formula with promising effects in treating migraines; however, its underlying mechanisms have not yet been clarified. AIM OF STUDY: The study aimed to evaluate WZYD's effectiveness in migraine treatment and investigate the potential mechanism of WZYD's effects on migraine and oxidative stress. MATERIALS AND METHODS: Behavior tests and immunofluorescence assay for the intensity of migraine markers to assess the migraine-relieving effect of WZYD after chronic migraine model induced by nitroglycerin in mice. The impacts of WZYD on oxidative stress-related markers, including reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase 1 (HO1), and NAD (P)H quinone oxidoreductase 1 (NQO1) in brain tissue were examined. In addition, protein expression or mRNA levels of the MZF1/PGK1 were detected using Western blot or PCR, respectively. Finally, the MZF1 overexpression vector was constructed to the higher level of MZF1. The MZF1/PGK1 signaling pathway expression was evaluated by markers of oxidative stress including NRF2 and others in this series of experiments. RESULTS: Through murine model experimentation, we observed that WZYD effectively alleviates migraine symptoms, signifying its therapeutic efficacy. Mechanistically, WZYD emerges as a potent activator of the NRF2, acting as a robust defense against oxidative stress. In vitro investigations demonstrated that WZYD combats oxidative stress and curbs cell apoptosis induced by these detrimental conditions. Furthermore, by suppressing the transcriptional expression of PGK1, an influential player in the NRF2 pathway, WZYD effectively activates NRF2 signaling. Intriguingly, we have identified MZF1 as the mediator orchestrating the regulation of the PGK1/NRF2 pathway by WZYD. CONCLUSION: The study confirms the effectiveness of WZYD in alleviating migraine symptoms. Mechanistically, WZYD activated the NRF2 signaling pathway; moreover, the action of WZYD involved the down-regulation of PGK1 mediated by MZF1, which promoted the activation of the NRF2 pathway. This study advances our understanding of the intricate mechanisms driving WZYD's efficacy, paving the way for novel treatments in migraine management.

Health care resource utilization and costs associated with diagnosed medication overuse headache and potential acute medication overuse in individuals with migraine.

OBJECTIVE: Estimate health care resource utilization and costs associated with medication overuse headache and potential acute medication overuse. METHODS: A retrospective analysis was conducted with Clinformatics Data Mart data (1 January 2019-31 December 2019) that included continuously enrolled commercially insured adults with migraine (International Classification of Diseases, Tenth Revision, Clinical Modification [ICD-10-CM] code G43.xxx). Medication overuse headache was defined as ≥1 inpatient or ≥2 outpatient claims with an ICD-10-CM code G44.41/40 (drug-induced headache). Potential acute medication overuse was defined as possessing sufficient medication for >10 mean treatment days/month for ergots, triptans, opioids, or combination analgesics or >15 mean cumulative days/month for simple prescription analgesics (e.g., acetaminophen, aspirin, other non-opioid analgesics) for >6 consecutive months. All-cause and migraine-related health care resource utilization and costs were compared after adjusting for demographic and clinical characteristics. RESULTS: Among 90,017 individuals with migraine, the frequency of medication overuse headache/potential acute medication overuse was 12.6% (diagnosed medication overuse headache: 0.6%; potential acute medication overuse: 12.1%). Adjusted all-cause total costs ($31,235 vs $21,486; difference: $9,749 [P < 0.001]) and adjusted migraine-related total costs ($9,770 vs $6,207; difference: $3,563 [P < 0.001]) were higher in the medication overuse headache/potential acute medication overuse group versus those without medication overuse headache/potential acute medication overuse. CONCLUSIONS: Individuals with diagnosed medication overuse headache/potential acute medication overuse had higher all-cause and migraine-related health care resource utilization and costs versus individuals without medication overuse headache/potential acute medication overuse, suggesting that improved migraine management is needed to reduce associated costs.

Cardiovascular Adverse Drug Reactions of Anti-Calcitonin Gene-Related Peptide Monoclonal Antibodies for Migraine Prevention: An Analysis from the European Spontaneous Adverse Event Reporting System.

INTRODUCTION: Anti-calcitonin gene-related peptide monoclonal antibodies (anti-CGRP-mAbs) have recently been approved for the prevention of migraine, and their safety profile is not fully characterized. OBJECTIVE: The aim of this study was to evaluate the adverse drug reactions (ADRs) of anti-CGRP-mAbs through the analysis of individual case safety reports (ICSRs) collected in the EudraVigilance (EV) database, with a specific focus on cardiovascular (CV) ADRs. METHODS: Data on ICSRs recorded between July 2018 and December 2022 in the EV database, involving one of the anti-CGRP-mAbs for migraine prevention-erenumab (ERE), galcanezumab (GMB), fremanezumab (FMB), and eptinezumab (EPT)-were included in the analysis. All ICSRs reporting at least one CV ADR, as identified within the MedDRA® System Organ Classes (SOCs) "cardiac disorders" or "vascular disorders," were selected for the analysis. The frequency of disproportionate reporting was expressed as the reporting odds ratio (ROR) with its 95% confidence interval (CI), to evaluate the frequency of reporting of CV ADRs for each anti-CGRP-mAb compared with all other monoclonal antibodies (mAbs). A case-by-case analysis was conducted paying particular attention to serious CV ADR reports, focusing on the type of seriousness, age group, sex, and concomitant drugs. RESULTS: A total of 9441 ICSRs were recorded in the EV database from 2018 to 2022, of which more than half were related to ERE (58.9%), followed by GMB (21.4%), FMB (19.0%), and EPT (0.7%). CV ICSRs accounted for 1205 cases (12.8%), with a total of 1599 CV ADRs. The CV ICSRs were mainly related to female patients (82.6%) aged 18-64 years (73.4%). Of the reported CV ADRs, 67.5% were considered serious. Among the total number of ICSRs related to each anti-CGRP-mAb, those associated with FMB had a higher percentage of CV ADRs (n = 253; 14.1%), followed by ERE (n = 707; 12.7%), EPT (n = 8; 12.7%), and GMB (n = 237; 11.7%). A higher frequency of reporting hypertension was shown for ERE (ROR = 1.45; 95% CI = 1.14-1.85). Pallor was mainly observed with FMB (5.00; 1.68-14.89), as well as deep vein thrombosis (3.86; 1.57-9.51), hot flush (2.16; 1.43-3.25), and palpitations (1.48; 1.05-2.08). Atrial fibrillation (2.36; 1.02-5.46) and myocardial infarction (2.21; 1.37-3.58) were mostly reported for GMB. CONCLUSION: The analysis of anti-CGRP-related CV ADRs was consistent with the information reported in the literature. However, hypertension with ERE, atrial fibrillation and myocardial infarction with GMB, as well as pallor, deep vein thrombosis, hot flush, and palpitations with FMB were not reported in the Summary of Product Characteristics (SmPCs). Considering this, more post-marketing analyses are needed to improve knowledge on the CV safety profiles of anti-CGRP-mAbs, especially for the last approved medication, EPT.

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.

Nonspecific analgesics, combination analgesics, and antiemetics.

The acute treatment of migraine attacks should provide rapid, effective, and long-lasting symptom relief, causing minimal adverse effects. For this purpose, there are several specific and nonspecific acute treatments. In this chapter, we focus on molecules not specifically designed for migraines, including anti-inflammatory not specific analgesics, such as acetaminophen, acetylsalicylic acid, and other non-steroidal anti-inflammatory drugs (or COX-2 inhibitors); antinausea medications like metoclopramide or prochlorperazine, which can alleviate sickness and vomiting associated with migraines, and may also have a direct painkiller effect; combinations of simple analgesics or association of a painkiller with caffeine. This stimulant can help enhance the pain-relieving effects of some headache medications and provide its own analgesic effect; physical approaches: applying cold packs or heating pads on the forehead or neck, can help relieve migraine pain; other classes with limited to no evidence to support their use, such as intravenous corticosteroids or antiepileptic drugs as sodium valproate. Finally, we will briefly mention opioids, barbiturates, or medical cannabis, bearing in mind that their use is not recommended by current guidelines.

Cumulative exposure to estrogen may increase the risk of migraine in women.

BACKGROUND: Migraine is a common disorder, particularly affecting women during their reproductive years. This female preponderance has been linked to exposure to female sex hormones. METHODS: We used self-reported data from women born in 1943-1965 enrolled in the Norwegian Women and Cancer Study to examine the differences between women with migraine and women without migraine in a prospective design with respect to both endogenous and exogenous female sex hormone exposure. RESULTS: In total, 62,959 women were included in the study, of whom 24.8% reported previous migraine (n = 15,635). Using a Cox proportional hazards model, we found that higher age at menarche reduced the risk of migraine (hazards ratio (HR) = 0.96, 95% confidence interval (CI) = 0.95-0.98) and that oral contraceptive use and parity increased the risk of migraine (HR = 1.12, 95% CI = 1.06-1.18 and HR = 1.37, 95% CI = 1.29-1.46, respectively). CONCLUSIONS: Older age at menarche appears to reduce migraine risk, whereas oral contraceptive use and having children appear to increase the risk. Further research is required to investigate the causality of these associations.