Pharmacological treatment of migraine: Drug classes, mechanisms of action, clinical trials and new treatments

Animal Models of Chronic Migraine: From the Bench to Therapy

PURPOSE OF REVIEW

Chronic migraine is a disabling progressive disorder without effective management approaches. Animal models have been developed and used in chronic migraine research. However, there are several problems with existing models. Therefore, we aimed to summarize and analyze existing animal models to facilitate translation from basic to clinical.

RECENT FINDINGS

The most commonly used models are the inflammatory soup induction model and the nitric oxide donor induction model. In addition, KATP openers have also been used in model induction. Based on the above models, some molecular targets have been identified, such as glutamate receptors. However, each model has its shortcomings and characteristics, and there are still some common problems that need to be solved, such as spontaneous headache, evaluation criteria after model establishment, and identification methods. In this review, we summarized and highlighted the advantages and limitations of the currently commonly used animal models of chronic migraine with a special focus on drug discovery and current therapeutic strategies, and discussed the directions that can be worked on in the future.

A Retrospective Analysis of Disease Epidemiology, Comorbidity Burden, Treatment Patterns, and Healthcare Resource Utilization of Migraine in the United Arab Emirates

INTRODUCTION

Migraine is a recurrent, disabling neurological disorder with a substantial global disease burden. However, limited real-world data are available on the patient characteristics, treatment patterns, comorbidities, and economic burden of migraine in the United Arab Emirates (UAE). In this study, we evaluated the disease burden, comorbidities, treatment patterns, specialties involved in migraine diagnosis, and healthcare resource utilization (HCRU) and associated costs in patients with migraine in Dubai, UAE.

METHODS

A retrospective, secondary database cohort study was conducted from 01 January 2014 to 31 March 2022 using the Dubai Real-World Database. Patients aged ≥ 18 years with at least one diagnosis claim for migraine with continuous enrollment during the study period were included. Patients were stratified into treatment sub-cohorts. Outcomes were evaluated in terms of clinical characteristics, comorbidities, specialists visited, treatment patterns, and HCRU.

RESULTS

The study included 203,222 patients (mean age: 40 years), with male predominance (55.4%). About 13.4% of patients had specific cardiovascular comorbidities. Frequently prescribed drug classes were nonsteroidal anti-inflammatory drugs (84.4%), triptans (29.8%), and beta-blockers (12.8%), while only 1.0% of patients with migraine were prescribed newer medications like calcitonin gene-related peptide antagonists. General medicine was the most frequently visited specialty on the index date (51.5%). The all-cause and migraine-specific median gross costs during the 12-month post-index period were US $1252.6 (2.4-564,740.7) and US $198.1 (0-168,903.3) respectively, with maximum contribution from inpatients. The contribution of migraine-specific median costs to all-cause median costs was highest for the diagnosis-related group (64.9%), followed by consumables (35.2%), medications (32.0%), procedures (24.5%), and services (24.5%).

CONCLUSION

Migraine significantly impacts healthcare costs in the UAE. The role of newer therapies in migraine management should be explored to reduce the associated socioeconomic burden and improve patients' quality of life.

Quality and reliability analysis of migraine Botox treatment information on YouTube

YouTube (YT) is one of the world's most well recognized video-sharing platforms that appeals to large audiences and is used by individuals to educate themselves on disease diagnosis and treatment alternatives and to distribute health-related information. Videos were searched by typing the terms "migraine botox" and "botox treatment for migraine" on the YT search bar in English. A total of 50 videos were evaluated for each term. Two independent researchers viewed the videos and documented pertinent descriptive attributes of each video, such as the upload date, number of comments, number of dislikes, number of likes, and views. The videos were analyzed and the DISCERN Global Quality Scale (GQS), Journal of the American Medical Association (JAMA) quality, and reliability scores were recorded. A total of 100 videos were assessed. The mean DISCERN score was 3.09, the mean JAMA score was 2.11, and the mean GQS score was 3.25. According to the source, 32% of the videos were uploaded by university/nonprofit physicians or professional organizations. In addition, when the DISCERN, GQS, and JAMA scores of the videos uploaded by health professionals were examined, a statistically significant difference was observed (P = .002, P = .015, and P = .002, respectively). However, no statistically significant relationship was found for the Video Popularity Index score. The reliability and quality scores of the evaluated videos uploaded by healthcare professionals for migraine Botox treatment were high, but the frequency of viewership was low. In our analysis of migraine Botox treatment videos on YT, we observed that the information on migraine Botox treatment had a wide spectrum, high-quality content, and that there were videos that may mislead viewers. In conclusion, we believe that the platform is not sufficient in its entirety, and that it should be supported with renewed, fact-checked, easy-to-understand language, and video-duration optimized videos.

Efficacy and Safety of Fluocinolone Acetonide Implant in Diabetic Macular Edema: Practical Guidelines from Reference Center

Diabetic macular edema (DME) is a common complication of diabetic retinopathy. Treatment with intravitreal injections is effective in most cases but is associated with a high therapeutic burden for patients. This implies the need for long-term treatments, such as the fluocinolone acetonide (FAc) implant. A review of basic science, pharmacology, and clinical data was conducted to provide a state-of-the-art view of the FAc implant in 2024. Although generally well tolerated, the FAc implant has been associated with ocular hypertension and cataract, and caution should be advised to the patients in this regard. By synthesizing information across these domains, a comprehensive evaluation can be attained, facilitating informed decision-making regarding the use of the FAc implant in the management of DME. The main objective of this review is to provide clinicians with guidelines on how to introduce and use the FAc implant in a patient with DME.

Cost of illness and labour market disaffiliation among patients with migraine discontinuing triptan treatment: A Danish nationwide register study from 1995 to 2021

BACKGROUND

Migraine presents significant health and economic challenges. Despite the widespread use of triptans, some patients discontinue them because of insufficient relief or adverse effects. Using national registers, the present study investigates the excess costs and labour market disaffiliation of Danish patients discontinuing triptan treatment.

METHODS

The study included all individuals ≥18 years ("patients") who discontinued redemption of triptan prescriptions between 1998 and 2019. They were categorized by number of distinct triptans redeemed before discontinuation: one, two or three or more. A control group was established from the general population without triptan redemptions, three per patient, matched by year of birth, sex and region of residence. We estimated excess direct and indirect costs from 5 years prior ("year -5") to 10 years post ("year 10") the first triptan redemption.

RESULTS

We identified 211,026 patients who discontinued triptan redemption, 82% after one, 14% after two and 4% after three or more distinct triptans. Over the period from year -5 to year 10, average excess healthcare costs per patient in these cohorts were EUR 9,554, EUR 10,942 and EUR 12,812 respectively. Over the same period, these patients earned EUR 27,964, EUR 35,920 and EUR 50,076 less than their respective controls, and received higher public transfer payments of EUR 20,181, EUR 23,264 and EUR 26,459.

CONCLUSIONS

Triptan discontinuers, who appear to have exhausted all current treatment avenues, face high direct and very high indirect excess costs attributable to migraine, and experience substantial increased labour market disaffiliation.

Challenges of Imaging the Greater Occipital Nerve Using Magnetic Resonance Imaging

ABSTRACT

Migraine headaches are a significant global health concern, frequently managed with varying levels of success. Compression of the greater occipital nerve (GON) is hypothesized to contribute to pathology in some migraine patients, making extracranial nerve decompression surgery a potential intervention for refractory cases. However, accurate methods to image the GON along its tortuous course still need to be explored. Our group has developed magnetic resonance imaging sequences to track the GON. Yet, many challenges were met, which included navigating the GON's complex anatomy, understanding anatomical variants, and designing advanced magnetic resonance imaging sequences and coils to image the posterior scalp. Addressing these hurdles is vital to capture and understand GON pathology and guide potential interventions.

[Migraine treatment consensus document of the Spanish Society of Neurology (SEN), Spanish Society of Family and Community Medicine (SEMFYC), Society of Primary Care Medicine (SEMERGEN) and Spanish Association of Migraine and Headache (AEMICE) on migraine treatment]

Migraine is a disease with a high prevalence and incidence, in addition to being highly disabling, causing a great impact on the patient's quality of life at a personal, family and work level, but also social, given its high expense due to its direct (care) and indirect (presenteeism and work absenteeism) costs. The multiple and recent developments in its pathophysiological knowledge and in its therapy require updating and, therefore, in this article the Spanish scientific societies most involved in its study and treatment (SEN, SEMFYC and SEMERGEN), together with the Association Spanish Association for Patients with Migraine and other Headaches (AEMICE), we have developed these updated care recommendations. We reviewed the treatment of migraine attacks, which consisted mainly of the use of NSAIDs and triptans, to which ditans and gepants have been added. We also discuss preventive treatment consisting of oral preventive drugs, botulinum toxin, and treatments that block the action of calcitonin-related peptide (CGRP). Finally, we emphasize that pharmacological treatments must be complementary to carrying out general measures consisting of identifying and managing/deletion the precipitating factors of the attacks and the chronicizing factors, controlling the comorbidities of migraine and eliminating analgesic overuse.

Acupoints for Headache with Blood Stasis Syndrome: a Literature Study Based on Data Mining Technology

Objective

This study aimed to investigate the features and underlying principles of acupuncture points used in the treatment of headaches associated with blood stasis syndrome.

Methods

Literature on the treatment of blood stasis headache with acupuncture and moxibustion was searched across three Chinese databases and one English database from January 1st, 2000, to January 1st, 2024. Relevant data including titles, journals, authors, keywords, interventions, main acupoints, and outcomes were extracted for further analysis.

Results

A total of 112 papers with 102 complete prescriptions were analyzed. Of the 77 acupoints examined, 72 were meridian points, and 5 were extraordinary points, used 699 times in total. The top ten acupoints by frequency were Fengchi (GB20), Taiyang (EX-HN5), Baihui (GV20), Hegu (LI4), Shuaigu (GB8), Taichong (LR3), Xuehai (SP10), Touwei (ST8), Geshu (BL17), and Waiguan (TE5). Yang meridian points were used more frequently than Yin meridian points (82.8% vs 17.2%), with the Gallbladder Meridian of Foot Shaoyang being the most common. Nearly half of the acupoints (49.9%) were on the head and neck, and 23.1% on the lower limbs. Specific acupoints accounted for 53.5% of the total frequency. Fengchi (GB20) and Taiyang (EX-HN5) showed the highest correlation. Association rule mining highlighted combinations like Fengchi (GB20) with Taiyang (EX-HN5) and Baihui (GV20). Cluster analysis yielded five clusters.

Conclusion

The study provides insights into selecting effective acupoints and combinations for clinical acupuncture practice and experimental studies in treating blood stasis headaches. Acupoints like Fengchi (GB20), Taiyang (EX-HN5), and Baihui (GV20) may be effective for clinical treatment, but further studies are needed to validate their efficacy.

Safety profile of lasmiditan: a retrospective post-marketing pharmacovigilance study based on the real-world data of FAERS database

BACKGROUND

Lasmiditan offers a promising option for the treatment of migraines, particularly for individuals with cardiovascular concerns. It is crucial to gather comprehensive safety information of lasmiditan through large-scale post market monitoring.

RESEARCH DESIGN AND METHODS

This study assessed the safety profile of lasmiditan based on real-world data of FDA Adverse Event Reporting System (FAERS) database. Four disproportionality analysis methods were applied to mining the significant signals. The differences in adverse event signals among different subgroups were investigated concerning race, sex, age, weight, dose, and concomitant drug.

RESULTS

A total of 820 reports and 1,661 adverse events with lasmiditan as the primary suspected drug were identified. Two new adverse event signals related to nervous system disorders emerged. Females and males were more likely to develop paresthesia and dizziness, respectively. Most common adverse events were more likely to occur in the elderly patients and at high doses.

CONCLUSIONS

It is essential to be vigilant about the relation of potential nervous system disorders with lasmiditan. The importance of heightened clinical vigilance regarding paresthesia in females and dizziness in males was underscored. Additionally, it is advised to administer a lower initial dose for elderly patients.

Preoperative visualization of the greater occipital nerve with magnetic resonance imaging in candidates for occipital nerve decompression for headaches

Occipital nerve decompression is effective in reducing headache symptoms in select patients with migraine and occipital neuralgia. Eligibility for surgery relies on subjective symptoms and responses to nerve blocks and Onabotulinum toxin A (Botox) injections. No validated objective method exists for detecting occipital headache pathologies. The purpose of the study is to explore the potential of high-resolution Magnetic Resolution Imaging (MRI) in identifying greater occipital nerve (GON) pathologies in chronic headache patients. The MRI protocol included three sequences targeting fat-suppressed fluid-sensitive T2-weighted signals. Visualization of the GON involved generating 2-D image slices with sequential rotation to track the nerve course. Twelve patients underwent pre-surgical MRI assessment. MRI identified four main pathologies that were validated against intra-operative examination: GON entanglement by the occipital artery, increased nerve thickness and hyperintensity suggesting inflammation compared to the non-symptomatic contralateral side, early GON branching with rejoining at a distal point, and a connection between the GON and the lesser occipital nerve. MRI possesses the ability to visualize the GON and identify suspected trigger points associated with headache symptoms. This case series highlights MRI's potential to provide objective evidence of nerve pathology. Further research is warranted to establish MRI as a gold standard for diagnosing extracranial contributors in headaches.

Identifying therapeutic target genes for migraine by systematic druggable genome-wide Mendelian randomization

BACKGROUND

Currently, the treatment and prevention of migraine remain highly challenging. Mendelian randomization (MR) has been widely used to explore novel therapeutic targets. Therefore, we performed a systematic druggable genome-wide MR to explore the potential therapeutic targets for migraine.

METHODS

We obtained data on druggable genes and screened for genes within brain expression quantitative trait locis (eQTLs) and blood eQTLs, which were then subjected to two-sample MR analysis and colocalization analysis with migraine genome-wide association studies data to identify genes highly associated with migraine. In addition, phenome-wide research, enrichment analysis, protein network construction, drug prediction, and molecular docking were performed to provide valuable guidance for the development of more effective and targeted therapeutic drugs.

RESULTS

We identified 21 druggable genes significantly associated with migraine (BRPF3, CBFB, CDK4, CHD4, DDIT4, EP300, EPHA5, FGFRL1, FXN, HMGCR, HVCN1, KCNK5, MRGPRE, NLGN2, NR1D1, PLXNB1, TGFB1, TGFB3, THRA, TLN1 and TP53), two of which were significant in both blood and brain (HMGCR and TGFB3). The results of phenome-wide research showed that HMGCR was highly correlated with low-density lipoprotein, and TGFB3 was primarily associated with insulin-like growth factor 1 levels.

CONCLUSIONS

This study utilized MR and colocalization analysis to identify 21 potential drug targets for migraine, two of which were significant in both blood and brain. These findings provide promising leads for more effective migraine treatments, potentially reducing drug development costs.

Genistein mitigates nitroglycerine-induced migraine: modulation of nitric oxide-mediated vasodilation and oxidative stress

Migraine is a widespread brain condition described by frequent, recurrent episodes of incapacitating, moderate-to-severe headaches with throbbing pain that are usually one-sided. It is the 2nd most debilitating state lived with disability in terms of years, with a prevalence rate of 15-20%. Significant drops in estrogen levels have been associated with triggering acute migraine attacks in certain cases. Phytoestrogens are plant-derived compounds that resemble estrogen in structure, enabling them to imitate estrogen's functions in the body by attaching to estrogen receptors. Thus, the study was aimed to explore the protective effect of genistein against migraine. Moreover, the role of nitric oxide was also studied in the observed effect of genistein. Nitric oxide (NO) is implicated in migraine pathophysiology due to its role in promoting cerebral vasodilation and modulation of pain perception. Exploring L-NAME, a nitric oxide synthase inhibitor in migraine research helps scientists better understand the role of NO in migraine. Nitroglycerine treatment significantly increased the facial-unilateral head pain and spontaneous pain, as evidenced by the increased number of head scratching and groomings. Nitroglycerine treatment also induced anxiogenic behavior in mice. A significant reduction in the number of entries in the light phase and open arm, respectively. Biochemical analysis indicated a significant increase in inflammatory and oxidative stress in the nitroglycerin group. A significant increase and decrease in brain TBARS and GSH were observed with nitroglycerine treatment, respectively. Moreover, nitroglycerine treatment has uplifted the serum TNF-α level. Genistein (20 mg/kg) significantly mitigated the facial-unilateral head pain, spontaneous pain, photophobia, and anxiety-like behavior induced by nitroglycerine. Biochemical analysis showed that genistein (20 mg/kg) significantly abrogated the nitroglycerine-induced lipid peroxidation and increased serum TNF-α level. Genistein treatment also upregulated the brain GSH level and downregulated the serum TNF-α level. The L-NAME-mediated alleviation of the protective effect of genistein might be attributed to the vasodilatory effect of L-NAME. Conclusively, it can be suggested that genistein might provide relief from migraine pain by inhibiting nitric oxide-mediated vasodilation and oxidative stress.

The Role of the Combination Paracetamol/Caffeine in Treatment of Acute Migraine Pain: A Narrative Review

INTRODUCTION

Thirty years ago, the first migraine-specific drugs (triptans) appeared. Today two new categories (gepants and ditans) are marketed for acute migraine treatment. That said, is there still a role for conventional therapy? The aim of the present narrative review is to provide an expert overview examining the possible role of the combination paracetamol/caffeine in treatment of acute migraine pain.

METHODS

To understand possible settings for more appropriate use of paracetamol/caffeine (1000 mg/130 mg) in treatment of acute migraine, a structured literature search was performed using the PubMed database by a panel of experts from major Italian headache centers; articles not referring to migraine pain were excluded from this review; review articles were prioritized.

RESULTS

Overall response, even to newer specific and selective trigeminal targeted drugs (TTTs), is not over 60%; thus, there is still room for conventional therapies in acute migraine treatment. The panel identified settings in which the use of paracetamol/caffeine combination to treat acute migraine attacks might offer benefit considering the consolidated use through years, despite the lack of studies directly addressing the efficacy of paracetamol/caffeine in the identified populations: subjects > 65 years of age; presence of cardiovascular (CV) comorbidities; TTTs non-responders; pregnancy and breastfeeding; subjects < 18 years of age; paracetamol/caffeine as add-on therapy.

CONCLUSIONS

Paracetamol is included in the World Health Organization (WHO) essential drug list and has a high level of popularity among patients. Caffeine enhances the analgesic effect of other drugs including paracetamol. In early treatment of acute migraine pain, prescribing physicians might consider using the paracetamol/caffeine combination among other options.

Untangling the mess of CGRP levels as a migraine biomarker: an in-depth literature review and analysis of our experimental experience

BACKGROUND

Calcitonin gene-related peptide (CGRP) is the most promising candidate to become the first migraine biomarker. However, literature shows clashing results and suggests a methodological source for such discrepancies. We aimed to investigate some of these methodological factors to evaluate the actual role of CGRP as biomarker.

METHODS

Previous to the experimental part, we performed a literature review of articles measuring CGRP in migraine patients. Using our 399 bio-bank sera samples, we performed a series of experiments to test the validity of different ELISA kits employed, time of sample processing, long-term storage, sampling in rest or after moderate exercise. Analysis of in-house data was performed to analyse average levels of the peptide and the effect of sex and age.

RESULTS

Literature review shows the high variability in terms of study design, determination methods, results and conclusions obtained by studies including CGRP determinations in migraine patients. CGRP measurements depends on the method and specific kit employed, also on the isoform detected, showing completely different ranges of concentrations. Alpha-CGRP and beta-CGRP had median with IQR levels of 37.5 (28.2-54.4) and 4.6 (2.4-6.4)pg/mL, respectively. CGRP content is preserved in serum within the 24 first hours when samples are stored at 4°C after clotting and immediate centrifugation. Storages at -80°C of more than 6 months result in a decrease in CGRP levels. Moderate exercise prior to blood extraction does not modulate the concentration of the peptide. Age positively correlates with beta-CGRP content and men have higher alpha-CGRP levels than women.

CONCLUSIONS

We present valuable information for CGRP measurements in serum. ELISA kit suitability should be tested prior to the experiments. Alpha and beta-CGRP levels should be analysed separately as they can show different behaviours even within the same condition. Samples can be processed in a 24-h window if they have been kept in 4°C and should not be stored for more than 6 months at -80°C before assayed. Patients do not need to rest before the blood extraction unless they have performed a high-endurance exercise. For comparative studies, sex and age should be accounted for as these parameters can impact CGRP concentrations.

Migraine and Its Treatment from the Medicinal Chemistry Perspective

Migraine is a disease of neurovascular origin that affects the quality of life of more than one billion people and ranks sixth among the most common diseases in the world. Migraine is characterized by a moderate or severe recurrent and throbbing headache, accompanied by nausea, vomiting, and photo-phonophobia. It usually starts in adolescence and is twice as common in women as in men. It is classified as with or without aura and has chronic or acute treatment types according to the frequency of occurrence. In acute treatment, analgesics that relieve pain in the fastest way are preferred, while there are different options in chronic treatment. While non-specific methods were used in the treatment of migraine until the 1950s, triptans, ditans, and CGRP-receptor-dependent therapies (monoclonal antibodies and gepants) started to be used in the clinic more recently. In this Review, we focus on the synthesis, side effects, and pharmacological and pharmacokinetic properties of FDA-approved drugs used in acute and preventive-specific treatment of migraine.

The association between dietary glycemic index and disease severity among the women with episodic migraine

PURPOSE

To our knowledge, no studies have evaluated the association between dietary glycemic index (GI) and glycemic load (GL) with migraine-related clinical symptoms.

METHODS

This cross-sectional study was conducted among 266 women with episodic migraine. The migraine disability assessment (MIDAS) was used to evaluate migraine-related disability in the recent three months. Visual analogue scales (VAS) were also employed to examine migraine-related pains. Glycemic index and glycemic load indices were calculated using the nutritional information obtained from the food frequency questionnaire.

RESULTS

The study participants had a mean age of 34.32 ± 7.86 years. It was observed that individuals in the quartile 4 of GI and GL reported significantly higher consumption of calories, carbohydrates, proteins, and fats (P < 0.05). In the unadjusted models, those in the quartile 4 of GI and GL had significantly increased odds of experiencing severe pain (based on VAS score) (OR = 2.09, 95% CI = 1.37-2.70, P < 0.001 for dietary GI, and OR = 1.75, 95% CI = 1.16-2.79, P = 0.005 for dietary GL). Additionally, compared to participants in the quartile 1 of GI and GL, those in the quartile 4 of GI and GL were more likely to suffer from severe disability (P < 0.05).

CONCLUSION

We found a significant positive correlation between the consumption of foods with higher GI and GL and the clinical conditions related to migraine disease. However, due to the cross-sectional nature of the study, it is not possible to establish a cause-and-effect relationship for the observed results.

Review of Personalized Medicine and Pharmacogenomics of Anti-Cancer Compounds and Natural Products

In recent years, the FDA has approved numerous anti-cancer drugs that are mutation-based for clinical use. These drugs have improved the precision of treatment and reduced adverse effects and side effects. Personalized therapy is a prominent and hot topic of current medicine and also represents the future direction of development. With the continuous advancements in gene sequencing and high-throughput screening, research and development strategies for personalized clinical drugs have developed rapidly. This review elaborates the recent personalized treatment strategies, which include artificial intelligence, multi-omics analysis, chemical proteomics, and computation-aided drug design. These technologies rely on the molecular classification of diseases, the global signaling network within organisms, and new models for all targets, which significantly support the development of personalized medicine. Meanwhile, we summarize chemical drugs, such as lorlatinib, osimertinib, and other natural products, that deliver personalized therapeutic effects based on genetic mutations. This review also highlights potential challenges in interpreting genetic mutations and combining drugs, while providing new ideas for the development of personalized medicine and pharmacogenomics in cancer study.

Computational biology approaches for drug repurposing

The drug discovery and development (DDD) process greatly relies on the data available in various forms to generate hypotheses for novel drug design. The complex and heterogeneous nature of biological data makes it difficult to utilize or gather meaningful information as such. Computational biology techniques have provided us with opportunities to better understand biological systems through refining and organizing large amounts of data into actionable and systematic purviews. The drug repurposing approach has been utilized to overcome the expansive time periods and costs associated with traditional drug development. It deals with discovering new uses of already approved drugs that have an established safety and efficacy profile, thereby, requiring them to go through fewer development phases. Thus, drug repurposing through computational biology provides a systematic approach to drug development and overcomes the constraints of traditional processes. The current chapter covers the basics, approaches and tools of computational biology that can be employed to effectively develop repurposing profile of already approved drug molecules.

Genetics of migraine: complexity, implications, and potential clinical applications

Migraine is a common neurological disorder with large burden in terms of disability for individuals and costs for society. Accurate diagnosis and effective treatments remain priorities. Understanding the genetic factors that contribute to migraine risk and symptom manifestation could improve individual management. Migraine has a strong genetic basis that includes both monogenic and polygenic forms. Some distinct, rare, familial migraine subtypes are caused by pathogenic variants in genes involved in ion transport and neurotransmitter release, suggesting an underlying vulnerability of the excitatory-inhibitory balance in the brain, which might be exacerbated by disruption of homoeostasis and lead to migraine. For more prevalent migraine subtypes, genetic studies have identified many susceptibility loci, implicating genes involved in both neuronal and vascular pathways. Genetic factors can also reveal the nature of relationships between migraine and its associated biomarkers and comorbidities and could potentially be used to identify new therapeutic targets and predict treatment response.

Evaluating Ubrogepant-related adverse events using the FDA adverse event reporting system

BACKGROUND

Migraine has a high prevalence in the population and accounts for 12% of primary headaches. Ubrogepant is used for the treatment of acute migraine, and although some clinical trials have demonstrated the safety of Ubrogepant, its long-term safety in a large sample of the population remains to be investigated.

METHODS

We collected data from the US Food and Drug Administration Adverse Event Reporting System (FAERS) database. We used reporting odds ratio (ROR), the proportional reporting ratio (PRR), the information component (IC) and the empirical Bayes geometric mean (EBGM) to evaluate Ubrogepant-induced adverse events (AEs).

RESULTS

We screened out 2,067 reports of Ubrogepant as primary suspected (PS) and 6,190 reports of Ubrogepant-induced AEs as PS. Our results showed that Ubrogepant-induced AEs targeted 4 system organ classes (SOCs), detected 32 Preferred terms (PTs) signals in 9 SOCs, including common Ubrogepant label consistent with Migraine, Nausea, Somnolence, Paraesthesia oral and Dizziness, It also includes the AEs of Hemiparesis, Mental impairment, Dysstasia, Tinnitus, Chest pain, Cold sweat, Neck pain, etc. that have not been demonstrated in previous studies.

CONCLUSIONS

Our study identified new AEs that have not been reported, which provides a new guidance to deepen the comprehension of the safety of Ubrogepant.

Rebalancing NOX2/Nrf2 to limit inflammation and oxidative stress across gut-brain axis in migraine

Migraine is one of the most common neurological illnesses, and it is characterized by complicated neurobiology. It was confirmed the influence of inflammation and oxidative stress in migraines and also in distal organs such as the intestine. Indeed, the constant bidirectional communication between the Central Nervous System (CNS) and the gastrointestinal (GI) tract, known as the gut-brain axis, has become an attractive target involved in different human disorders. Herein, we explored the role of NADPH oxidase 2 (NOX2) in nitroglycerin (NTG)-induced migraine in mice models to discover the mechanism by which, during migraine attack, oxidative stress is sustained within trigeminal neurons and GI. Considering the inverse relationship between NOX2 and Nrf2, Nrf2 upregulation seems to be a promising approach to decrease NOX2 expression and consequently limit oxidative stress and inflammation spread in neurological and non-neurological diseases. With this aim, we exploited tempol's Nrf2-inducer ability to better understand the involvement of Nrf2/NOX2 axis in migraine and associated GI comorbidities. Behavioral tests confirmed that tempol, in a dose-dependent manner, moderated clinical signs of migraine and abdominal pain. Moreover, we demonstrated that the decrease in migraine-related symptomatology was strongly linked to the modulation of Nrf2/NOX2 signaling pathway in the brain and colon. In the brain, the rebalancing of Nrf2/NOX2 prevented neuronal loss, decreased glia reactivity while inhibiting NF-κB and NLRP3 inflammasome activation. In the colon, Nrf2 upregulation and consequent NOX2 decrease reduced the histological damage, mast cells infiltration as well as tumor necrosis factor (TNF)-α and interleukin (IL)-1β release. Furthermore, the attenuation of inflammation and oxidative stress led to the restoration of the intestinal barrier through TJs replacement. Taken as a whole, data suggested that the regulation of Nrf2/NOX2 balance is a successful way to reduce neurological and related intestinal impairments during migraine and could be of relevance for migraine-like attacks in humans.

Drug-related side effects and adverse reactions in the treatment of migraine: a bibliometric and visual analysis

Background

Migraine imposes a substantial global burden, impacting patients and society. Pharmacotherapy, as a primary treatment, entails specific adverse reactions. Emphasizing these reactions is pivotal for improving treatment strategies and enhancing patients' well-being. Thus, we conducted a comprehensive bibliometric and visual analysis of relevant literature.

Methodology

We conducted a comprehensive search on the Science Citation Index Expanded within the Web of Science, restricting the literature for analysis based on criteria such as document type, publication date, and language. Subsequently, we utilized various analytical tools, including VOSviewer, Scimago Graphica, the R package 'bibliometrix', CiteSpace, and Excel programs, for a meticulous examination and systematic organization of data concerning journals, authors, countries/regions, institutions, keywords, and references.

Results

By August 31, 2023, the literature was distributed across 379 journals worldwide, authored by 4,235 individuals from 1726 institutions. It featured 2,363 keywords and 38,412 references. 'HEADACHE' led in publication count, with 'SILBERSTEIN S' as the most prolific author. The United States ranked highest in publication volume, with 'UNIV COPENHAGEN' leading among institutions.

Conclusion

Our research findings indicate that researchers in the field continue to maintain a focus on the calcitonin gene-related peptide (CGRP) system and explore diverse mechanisms for drug development through the application of novel biotechnological approaches. Furthermore, it is imperative to enhance the assessment of clinical trial outcomes, consistently monitor the efficacy and safety of prominent drugs such as Erenumab and Fremanezumab. There is a need for further evaluation of acute and preventive treatments tailored to different populations and varying types of migraine.

Drug-related side effects and adverse reactions in the treatment of migraine: a bibliometric and visual analysis

BACKGROUND

Migraine imposes a substantial global burden, impacting patients and society. Pharmacotherapy, as a primary treatment, entails specific adverse reactions. Emphasizing these reactions is pivotal for improving treatment strategies and enhancing patients' well-being. Thus, we conducted a comprehensive bibliometric and visual analysis of relevant literature.

METHODOLOGY

We conducted a comprehensive search on the Science Citation Index Expanded within the Web of Science, restricting the literature for analysis based on criteria such as document type, publication date, and language. Subsequently, we utilized various analytical tools, including VOSviewer, Scimago Graphica, the R package 'bibliometrix', CiteSpace, and Excel programs, for a meticulous examination and systematic organization of data concerning journals, authors, countries/regions, institutions, keywords, and references.

RESULTS

By August 31, 2023, the literature was distributed across 379 journals worldwide, authored by 4,235 individuals from 1726 institutions. It featured 2,363 keywords and 38,412 references. 'HEADACHE' led in publication count, with 'SILBERSTEIN S' as the most prolific author. The United States ranked highest in publication volume, with 'UNIV COPENHAGEN' leading among institutions.

CONCLUSION

Our research findings indicate that researchers in the field continue to maintain a focus on the calcitonin gene-related peptide (CGRP) system and explore diverse mechanisms for drug development through the application of novel biotechnological approaches. Furthermore, it is imperative to enhance the assessment of clinical trial outcomes, consistently monitor the efficacy and safety of prominent drugs such as Erenumab and Fremanezumab. There is a need for further evaluation of acute and preventive treatments tailored to different populations and varying types of migraine.

Preventive treatment patterns in the adult migraine population: an observational UK study over 7 years

BACKGROUND

Calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) are recommended by the United Kingdom National Institute of Health and Care Excellence for the prevention of migraine as treatment beyond third line. We report migraine prevalence and preventive treatment patterns in the adult United Kingdom primary care population over a 7.5-year period, focusing on patients ceasing ≥ 3 oral preventive medication classes.

METHODS

Study populations were retrieved from the Clinical Practice Research Datalink GOLD database (study period: 19 September 2012 to 1 January 2020; inclusion criteria: ≥12 months follow-up, current-in-dataset, adult on 1 January 2020). Patients who used ≥ 1 oral preventive medication with ≥ 3-year follow-up after first prescription were considered preventive treatment users; class cessation was defined as cessation without evidence of restart within 6 months from end-of-supply date.

RESULTS

On 1 January 2020, 3.0% of the total study population were diagnosed with migraine (n = 81,190/2,664,306); of these, 42.4% were preventive treatment users (n = 34,448/81,190). The most frequently used oral migraine preventive medication classes were beta-blockers (n = 14,713), tricyclic antidepressants (n = 14,415) and antiepileptics (n = 6497). Among preventive treatment users, 7.7% (n = 2653/34,448) ceased ≥ 3 oral preventive medication classes; of these, 21.7% (n = 576/2653) had been referred to a neurologist.

CONCLUSIONS

Compared to existing population-based estimates of migraine prevalence, our data further corroborates that a considerable proportion of patients with migraine do not seek treatment. Among those who sought primary care within a 7.5-year period, almost half received empirical oral preventive treatment. Importantly, nearly 1 of 10 preventive treatment users ceased ≥ 3 oral preventive medication classes, highlighting a need for additional therapeutic options. These patients may benefit from CGRP antagonists and/or injectable onabotulinumtoxinA; however, only a minority was referred to specialist care, where these options would be more available.

TRIAL REGISTRATION

Not applicable.

Neurovascular Compression-Induced Intracranial Allodynia May Be the True Nature of Migraine Headache: an Interpretative Review

PURPOSE OF REVIEW

Surgical deactivation of migraine trigger sites by extracranial neurovascular decompression has produced encouraging results and challenged previous understanding of primary headaches. However, there is a lack of in-depth discussions on the pathophysiological basis of migraine surgery. This narrative review provides interpretation of relevant literature from the perspective of compressive neuropathic etiology, pathogenesis, and pathophysiology of migraine.

RECENT FINDINGS

Vasodilation, which can be asymptomatic in healthy subjects, may produce compression of cranial nerves in migraineurs at both extracranial and intracranial entrapment-prone sites. This may be predetermined by inherited and acquired anatomical factors and may include double crush-type lesions. Neurovascular compression can lead to sensitization of the trigeminal pathways and resultant cephalic hypersensitivity. While descending (central) trigeminal activation is possible, symptomatic intracranial sensitization can probably only occur in subjects who develop neurovascular entrapment of cranial nerves, which can explain why migraine does not invariably afflict everyone. Nerve compression-induced focal neuroinflammation and sensitization of any cranial nerve may neurogenically spread to other cranial nerves, which can explain the clinical complexity of migraine. Trigger dose-dependent alternating intensity of sensitization and its synchrony with cyclic central neural activities, including asymmetric nasal vasomotor oscillations, may explain the laterality and phasic nature of migraine pain. Intracranial allodynia, i.e., pain sensation upon non-painful stimulation, may better explain migraine pain than merely nociceptive mechanisms, because migraine cannot be associated with considerable intracranial structural changes and consequent painful stimuli. Understanding migraine as an intracranial allodynia could stimulate research aimed at elucidating the possible neuropathic compressive etiology of migraine and other primary headaches.

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.

The Epigenetics of Migraine

Migraine is a complex neurological disorder and a major cause of disability. A wide range of different drug classes such as triptans, antidepressants, anticonvulsants, analgesics, and beta-blockers are used in acute and preventive migraine therapy. Despite a considerable progress in the development of novel and targeted therapeutic interventions during recent years, e.g., drugs that inhibit the calcitonin gene-related peptide (CGRP) pathway, therapy success rates are still unsatisfactory. The diversity of drug classes used in migraine therapy partly reflects the limited perception of migraine pathophysiology. Genetics seems to explain only to a minor extent the susceptibility and pathophysiological aspects of migraine. While the role of genetics in migraine has been extensively studied in the past, the interest in studying the role of gene regulatory mechanisms in migraine pathophysiology is recently evolving. A better understanding of the causes and consequences of migraine-associated epigenetic changes could help to better understand migraine risk, pathogenesis, development, course, diagnosis, and prognosis. Additionally, it could be a promising avenue to discover new therapeutic targets for migraine treatment and monitoring. In this review, we summarize the state of the art regarding epigenetic findings in relation to migraine pathogenesis and potential therapeutic targets, with a focus on DNA methylation, histone acetylation, and microRNA-dependent regulation. Several genes and their methylation patterns such as CALCA (migraine symptoms and age of migraine onset), RAMP1, NPTX2, and SH2D5 (migraine chronification) and microRNA molecules such as miR-34a-5p and miR-382-5p (treatment response) seem especially worthy of further study regarding their role in migraine pathogenesis, course, and therapy. Additionally, changes in genes including COMT, GIT2, ZNF234, and SOCS1 have been linked to migraine progression to medication overuse headache (MOH), and several microRNA molecules such as let-7a-5p, let-7b-5p, let-7f-5p, miR-155, miR-126, let-7g, hsa-miR-34a-5p, hsa-miR-375, miR-181a, let-7b, miR-22, and miR-155-5p have been implicated with migraine pathophysiology. Epigenetic changes could be a potential tool for a better understanding of migraine pathophysiology and the identification of new therapeutic possibilities. However, further studies with larger sample sizes are needed to verify these early findings and to be able to establish epigenetic targets as disease predictors or therapeutic targets.

A comprehensive review on pharmacological applications and drug-induced toxicity of valproic acid

Valproic acid, a branching short chain fatty acid, is a popular drug to treat epilepsy and acts as a mood-stabilizing drug. The obstruction of ion channels and Gamma Amino Butyrate transamino butyrate GABA has been linked to antiepileptic effects. Valproic acid has been characterized as a Histone deacetylase inhibitor, functioning directly transcription of gene levels by blocking the deacetylation of histones and increasing the accessibility of transcription sites. Study has been extensively focused on pharmaceutical activity of valproic acid through various pharmacodynamics activity from absorption, distribution and excretion particularly in patients who are resistant to or intolerant of lithium or carbamazepine, as well as those with mixed mania or rapid cycling.

Revisiting Migraine: The Evolving Pathophysiology and the Expanding Management Armamentarium

Migraine affects about one billion people worldwide yearly and is one of the most common neurologic illnesses, with a high prevalence and morbidity, particularly among young adults and females. Migraine is associated with many comorbidities, including stress, sleep difficulties, and suicidal ideation. Migraine, despite its widespread occurrence, is underdiagnosed and undertreated. Because of the complicated and primarily unknown mechanisms of migraine formation, several social and biological risk factors, such as hormone imbalances, genetic and epigenetic impacts, and cardiovascular, neurological, and autoimmune illnesses, have been proposed. Through the mid-20th century diversion of the now-defunct vascular theory, the pathophysiology of migraine has developed from a historical study of the "humours" to a distinct entity as a neurological disorder. The range of therapeutic targets has broadened significantly, increasing the number of specialized clinical trials. Understanding the biology of migraine through careful research has resulted in the identification of major therapeutic classes: (i) triptans, serotonin 5-HT1B/1D receptor agonists, (ii) gepants, calcitonin gene-related peptide (CGRP) receptor antagonists, (iii) ditans, 5-HT1F receptor agonists, (iv) CGRP monoclonal antibodies, and (v) glurants, mGlu5 modulators, with further targets being explored. This review provides a comprehensive overview of the most recent literature on epidemiology and risk factors and exposes knowledge gaps.

Digital Therapeutics in Migraine Management: A Novel Treatment Option in the COVID-19 Era

Migraine is a chronic and often lifelong disease that directly affects over one billion people globally. Because access to migraine medical services is limited, only a minority of migraine patients are treated adequately. This situation worsened during the COVID-19 pandemic. Digital therapeutics (DTx) is an emerging therapeutic approach that opens up many new possibilities for remote migraine management. For instance, migraine management tools, online migraine diagnosis, guideline-based treatment options, digitally networked patients, and collecting anonymized information about migraine attacks and course parameters for scientific evaluation. Various applications of DTx in migraine management have been studied in recent years, such as the usefulness of digital migraine self-management tools in diagnosing and tracking migraine attacks, and the efficacy and safety of digital cognitive behavioural therapy. However, the development of DTx is still in its infancy and still faces many obstacles. The primary goal of this study is to review the latest research on DTx in migraine management, identify challenges, and outline future trends.

Bipartite Activation of Sensory Neurons by a TRPA1 Agonist Allyl Isothiocyanate Is Reflected by Complex Ca2+ Influx and CGRP Release Patterns: Enhancement by NGF and Inhibition with VAMP and SNAP-25 Cleaving Botulinum Neurotoxins

The trafficking of transient receptor potential (TRP) channels to the plasma membrane and the release of calcitonin gene-related peptide (CGRP) from trigeminal ganglion neurons (TGNs) are implicated in some aspects of chronic migraines. These exocytotic processes are inhibited by cleavage of SNAREs with botulinum neurotoxins (BoNTs); moreover, type A toxin (/A) clinically reduces the frequency and severity of migraine attacks but not in all patients for unknown reasons. Herein, neonatal rat TGNs were stimulated with allyl isothiocyanate (AITC), a TRPA1 agonist, and dose relationships were established to link the resultant exocytosis of CGRP with Ca2+ influx. The CGRP release, quantified by ELISA, was best fit by a two-site model (EC50 of 6 and 93 µM) that correlates with elevations in intracellular Ca2+ [Ca2+]i revealed by time-lapse confocal microscopy of fluo-4-acetoxymethyl ester (Fluo-4 AM) loaded cells. These signals were all blocked by two TRPA1 antagonists, HC-030031 and A967079. At low [AITC], [Ca2+]i was limited because of desensitisation to the agonist but rose for concentrations > 0.1 mM due to a deduced non-desensitising second phase of Ca2+ influx. A recombinant BoNT chimera (/DA), which cleaves VAMP1/2/3, inhibited AITC-elicited CGRP release to a greater extent than SNAP-25-cleaving BoNT/A. /DA also proved more efficacious against CGRP efflux evoked by a TRPV1 agonist, capsaicin. Nerve growth factor (NGF), a pain-inducing sensitiser of TGNs, enhanced the CGRP exocytosis induced by low [AITC] only. Both toxins blocked NGF-induced neuropeptide secretion and its enhancement of the response to AITC. In conclusion, NGF sensitisation of sensory neurons involves TRPA1, elevated Ca2+ influx, and CGRP exocytosis, mediated by VAMP1/2/3 and SNAP-25 which can be attenuated by the BoNTs.

Antiseizure Medications for the Prophylaxis of Migraine during the Anti- CGRP Drugs Era

Migraine and epilepsy are fundamentally distinct disorders that can frequently coexist in the same patient. These two conditions significantly differ in diagnosis and therapy but share some widely- used preventive treatments. Antiseizure medications (ASMs) are the mainstay of therapy for epilepsy, and about thirty different ASMs are available to date. ASMs are widely prescribed for other neurological and non-neurological conditions, including migraine. However, only topiramate and valproic acid/valproate currently have an indication for migraine prophylaxis supported by high-quality evidence. Although without specifically approved indications and with a low level of evidence or recommendation, several other ASMs are used for migraine prophylaxis. Understanding ASM antimigraine mechanisms, including their ability to affect the pro-migraine calcitonin gene-related peptide (CGRP) signaling pathway and other pathways, may be instrumental in identifying the specific targets of their antimigraine efficacy and may increase awareness of the neurobiological differences between epilepsy and migraine. Several new ASMs are under clinical testing or have been approved for epilepsy in recent years, providing novel potential drugs for migraine prevention to enrich the treatment armamentarium and drugs that inhibit the CGRP pathway.

Gepants for Acute and Preventive Migraine Treatment: A Narrative Review

Calcitonin gene-related peptide (CGRP) antagonists are a class of medications that act as antagonists of the CGRP receptor or ligand. They can be divided into monoclonal antibodies and non-peptide small molecules, also known as gepants. CGRP antagonists were the first oral agents specifically designed to prevent migraines. The second generation of gepants includes rimegepant (BHV-3000, BMS-927711), ubrogepant (MK-1602), and atogepant (AGN-241689, MK-8031). Zavegepant (BHV-3500, BMS-742413) belongs to the third generation of gepants characterized by different administration routes. The chemical and pharmacological properties of this new generation of gepants were calculated. The clinical trials showed that the new generation of CGRP antagonists is effective for the acute and/or preventive treatment of migraines. No increased mortality risks were observed to be associated with the second- and third-generation gepants. Moreover, the majority of the serious adverse events reported probably occurred unrelated to the medications. Interesting facts about gepants were highlighted, such as potency, hepatotoxicity, concomitant use with monoclonal antibodies targeting the CGRP, comparative analysis with triptans, and the "acute and preventive" treatment of migraine. Further studies should include an elderly population and compare the medications inside this class and with triptans. There are still concerns regarding the long-term side effects of these medications, such as chronic vascular hemodynamic impairment. Meanwhile, careful pharmacovigilance and safety monitoring should be performed in the clinical practice use of gepants.

The Virtual "Enfacement Illusion" on Pain Perception in Patients Suffering from Chronic Migraine: A Study Protocol for a Randomized Controlled Trial

BACKGROUND

given the limited efficacy, tolerability, and accessibility of pharmacological treatments for chronic migraine (CM), new complementary strategies have gained increasing attention. Body ownership illusions have been proposed as a non-pharmacological strategy for pain relief. Here, we illustrate the protocol for evaluating the efficacy in decreasing pain perception of the enfacement illusion of a happy face observed through an immersive virtual reality (VR) system in CM.

METHOD

the study is a double-blind randomized controlled trial with two arms, involving 100 female CM patients assigned to the experimental group or the control group. The experimental group will be exposed to the enfacement illusion, whereas the control group will be exposed to a pleasant immersive virtual environment. Both arms of the trial will consist in three VR sessions (20 min each). At the baseline and at the end of the intervention, the patients will fill in questionnaires based on behavioral measures related to their emotional and psychological state and their body satisfaction. Before and after each VR session, the level of pain, the body image perception, and the affective state will be assessed.

DISCUSSION

this study will provide knowledge regarding the relationship between internal body representation and pain perception, supporting the effectiveness of the enfacement illusion as a cognitive behavioral intervention in CM.

Prevention of Migraine

Migraine, a primary headache disorder is a chronic and complex neurological disease that affects millions of people worldwide, impacting their quality of life. It is one of the most common reasons why individuals seek the advice of their physician, and is one of the most common referrals seen in the offices of general neurologists and headache specialists. In the past decade, there has been robust research on not only the pathophysiology of migraine but in the efforts to treat and, importantly, prevent. The introduction of calcitonin gene related peptide antagonists (CGRP-A) have opened new doors for preventive treatment options. OnabotulinumtoxinA (BoNTA) has remained a staple in the treatment of chronic migraine with data emerging with combination therapy. Neurostimulation has offered additional nonpharmacologic approaches to migraine treatment. In addition to lifestyle and behavioral modifications, these have changed the landscape of migraine prevention.

Epigenetic Connection of the Calcitonin Gene-Related Peptide and Its Potential in Migraine

The calcitonin gene-related peptide (CGRP) is implicated in the pathogenesis of several pain-related syndromes, including migraine. Targeting CGRP and its receptor by their antagonists and antibodies was a breakthrough in migraine therapy, but the need to improve efficacy and limit the side effects of these drugs justify further studies on the regulation of CGRP in migraine. The expression of the CGRP encoding gene, CALCA, is modulated by epigenetic modifications, including the DNA methylation, histone modification, and effects of micro RNAs (miRNAs), circular RNAs, and long-coding RNAs (lncRNAs). On the other hand, CGRP can change the epigenetic profile of neuronal and glial cells. The promoter of the CALCA gene has two CpG islands that may be specifically methylated in migraine patients. DNA methylation and lncRNAs were shown to play a role in the cell-specific alternative splicing of the CALCA primary transcript. CGRP may be involved in changes in neural cytoarchitecture that are controlled by histone deacetylase 6 (HDAC6) and can be related to migraine. Inhibition of HDAC6 results in reduced cortical-spreading depression and a blockade of the CGRP receptor. CGRP levels are associated with the expression of several miRNAs in plasma, making them useful peripheral markers of migraine. The fundamental role of CGRP in inflammatory pain transmission may be epigenetically regulated. In conclusion, epigenetic connections of CGRP should be further explored for efficient and safe antimigraine therapy.

Association between migraine prevalence, treatment with proton-pump inhibitors and CYP2C19 phenotypes in UK Biobank

Proton-pump inhibitors (PPIs) are used to suppress gastric acid secretion in several gastrointestinal conditions. While these drugs are generally well tolerated, their long-term use may be associated with different adverse effects, including migraine. We analyzed the association between treatment with PPIs (omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole) and migraine prevalence in the UK Biobank cohort through a cross-sectional analysis (using baseline data for 468,280 participants, 16,390 of whom had migraine) and a longitudinal analysis (including 145,007 participants with no migraine at baseline, of whom 3786 had probable migraine without aura [MWOA] and 9981 probable migraine with aura [MWA] or both MWOA and MWA at an average follow-up time of 10.06 years). We also evaluated the modulating role of the metabolizer phenotype of CYP2C19, the major enzyme involved in PPI clearance. Treatment with PPIs was associated with higher migraine prevalence at baseline (odds ratio [OR] = 1.25, p < 0.0001). CYP2C19 rapid metabolizer phenotype was associated with lower prevalence of migraine exclusively in participants treated with PPIs (OR = 0.89, p = 0.029). In addition, treatment with PPIs was associated with higher incidence of both probable MWOA (OR = 1.24, p = 0.002) and MWA (OR = 1.43, p < 0.0001) at follow-up. Treatment with PPIs and CYP2C19 poor metabolizer status were associated with higher incidence of probable chronic migraine exclusively in men. Our results suggest a significant association between treatment with PPIs and migraine in this large population-based cohort and support a potential relevant role of gender and CYP2C19 phenotype.