Pathophysiology of Migraine: A Disorder of Sensory Processing

Neuron-glia crosstalk and inflammatory mediators in migraine pathophysiology

Migraine is a complex neurological disorder with neuroinflammation playing a crucial role in its pathogenesis. This review provides an overview of the neuroinflammation mechanisms in migraine, focusing on both cellular and molecular aspects. At the cellular level, we examine the role of glial cells, including astrocytes, microglia, oligodendrocytes in the central nervous system, and Schwann cells and satellite glial cells in the peripheral nervous system. On the molecular level, we explore the signaling pathways, including IL-1β, TNF-α, IL-6, and non-coding RNAs, that mediate cell interactions or independent actions. Some of the molecular signaling pathways mentioned, such as TNF-α and IL-1β, have been investigated as druggable targets. Recent advancements, such as [11C] PBR28-targeted imaging for visualizing astrocyte activation and single-cell sequencing for exploring cellular heterogeneity, represent breakthroughs in understanding the mechanisms of neuroinflammation in migraine. By considering factors for personalized treatments, estrogen and TRPM8 emerge as promising therapeutic targets regarding sexual dimorphism. These advancements may help bridge the gap between preclinical findings and clinical applications, ultimately leading to more precise and personalized options for migraine patients.

Pituitary adenylate cyclase-activating polypeptide signalling as a therapeutic target in migraine

Migraine is a disabling neurological disorder that affects more than one billion people worldwide. The clinical presentation is characterized by recurrent headache attacks, which are often accompanied by photophobia, phonophobia, nausea and vomiting. Although the pathogenesis of migraine remains incompletely understood, mounting evidence suggests that specific signalling molecules are involved in the initiation and modulation of migraine attacks. These signalling molecules include pituitary adenylate cyclase-activating polypeptide (PACAP), a vasoactive peptide that is known to induce migraine attacks when administered by intravenous infusion to people with migraine. Discoveries linking PACAP to migraine pathogenesis have led to the development of drugs that target PACAP signalling, and a phase II trial has provided evidence that a monoclonal antibody against PACAP is effective for migraine prevention. In this Review, we explore the molecular and cellular mechanisms of PACAP signalling, shedding light on its role in the trigeminovascular system and migraine pathogenesis. We then discuss emerging therapeutic strategies that target PACAP signalling for the treatment of migraine and consider the research needed to translate the current knowledge into a treatment for migraine in the clinic.

The impact of genetic factors on the response to migraine therapy

Migraine is a multidimensional disease affecting a large portion of the human population presenting with a variety of symptoms. In the era of personalized medicine, successful migraine treatment presents a challenge, as several studies have shown the impact of a patient's genetic profile on therapy response. However, with the emergence of contemporary treatment options, there is promise for improved outcomes. A literature search was conducted in PubMed and Scopus, in order to obtain studies investigating the impact of genetic factors on migraine therapy outcome. Overall, 23 studies were included in the current review, exhibiting diversity in the treatments used and the genetic variants investigated. Divergent genes were assessed for each category of migraine treatment. Several genetic factors were identified to contribute to the heterogeneous response to treatment. SNPs related to pharmacodynamic receptors, pharmacogenetics and migraine susceptibility loci were the most investigated variants, revealing some interesting significant results. To date, various associations have been recorded correlating the impact of genetic factors on migraine treatment responses. More extensive research needs to take place with the aim of shedding light on the labyrinthine effects of genetic variations on migraine treatment, and, consequently, these findings can promptly affect migraine treatment and improve migraine patients' life quality in the vision of precise medicine.

Causal relationships between cortical brain structural alterations and migraine subtypes: a bidirectional Mendelian randomization study of 2,347 neuroimaging phenotypes

BACKGROUND

Previous studies have shown that migraines are associated with brain structural changes. However, the causal relationships between these changes and migraine, as well as its subtypes, migraine with aura (MA) and migraine without aura (MO), remain largely unclear.

METHODS

We utilized genome-wide association study (GWAS) summary statistics from European cohorts for 2,347 cortical structural magnetic resonance imaging (MRI) phenotypes, derived from both T1-weighted and diffusion tensor imaging scans (n = 36,663), with migraine and its subtypes (n = 147,970-375,752). Cortical phenotypes included both macrostructural (e.g., cortical thickness, surface area) and microstructural (e.g., fractional anisotropy, mean diffusivity) features. Genetic correlations were first assessed to identify significant associations, followed by bidirectional Mendelian randomization (MR) analyses to determine causal relationships between these brain phenotypes and migraine, as well as its subtypes (MA and MO). Sensitivity analyses were applied to ensure the robustness of the results.

RESULTS

Genetic correlation analysis identified 510 significant associations between cortical structural phenotypes and migraine across 401 distinct traits. Forward MR analysis revealed nine significant causal effects of cortical structural changes on migraine risk. Specifically, increased cortical thickness and local gyrification index in specific cortical regions were associated with a decreased risk of overall migraine, MA, and MO, while intracellular volume fraction and orientation diffusion index in specific regions increased the risk of MA and MO. Reverse MR analysis demonstrated that MA causally increased mean diffusivity in the insular and frontal opercular cortex. Sensitivity analyses confirmed the robustness of these findings, with no evidence of horizontal pleiotropy or heterogeneity.

CONCLUSION

This study identifies causal relationships between cortical neuroimaging phenotypes and migraine, highlighting potential biomarkers for migraine diagnosis, treatment, and prevention.

The Trigeminal Sensory System and Orofacial Pain

The trigeminal sensory system consists of the trigeminal nerve, the trigeminal ganglion, and the trigeminal sensory nuclei (the mesencephalic nucleus, the principal nucleus, the spinal trigeminal nucleus, and several smaller nuclei). Various sensory signals carried by the trigeminal nerve from the orofacial area travel into the trigeminal sensory system, where they are processed into integrated sensory information that is relayed to higher sensory brain areas. Thus, knowledge of the trigeminal sensory system is essential for comprehending orofacial pain. This review elucidates the individual nuclei that comprise the trigeminal sensory system and their synaptic transmission. Additionally, it discusses four types of orofacial pain and their relationship to the system. Consequently, this review aims to enhance the understanding of the mechanisms underlying orofacial pain.

Incorporating Therapeutic Education and Exercise in Migraine Management: A Biobehavioral Approach

The main objective was to perform a description of the potential biobehavioral factors that influence disability in patients with migraines and develop a multimodal physiotherapy treatment proposal incorporating therapeutic education and exercise prescription, applying a biobehavioral approach. This manuscript highlights the complex interplay between migraines and physical activity, with many migraine sufferers performing reduced physical activity, even during headache-free intervals. The kinesiophobia present in a significant portion of patients with migraine exacerbates functional disability and compromises quality of life. Psychological elements, especially pain catastrophizing, depression, and self-efficacy, further compound migraine-related disability. Addressing these issues requires a multidisciplinary approach that integrates physical activity and behavioral interventions. We propose a therapeutic education model of motor behavior that emphasizes the enhancement of therapeutic exercise outcomes. This model consists of the four following phases: (1) biobehavioral analysis of movement; (2) goal setting; (3) education about exercise benefits; and (4) movement education. A notable feature is the incorporation of motivational interviewing, a communication strategy that amplifies intrinsic motivation for change. Recent clinical guidelines have advocated for specific exercise modalities to ameliorate migraine symptoms. However, we highlight the importance of a tailored exercise prescription to maximize the benefits of exercise and reduce the possible adverse effects. The integration of exercise with other lifestyle recommendations, such as maintaining consistent sleep patterns and employing stress management techniques, is pivotal for improving outcomes in patients with migraine. Although evidence supports the benefits of these interventions in various painful conditions, further research is needed to establish their efficacy specifically for migraine management.

Understanding the efficacy and tolerability of migraine treatment: a deep dive into CGRP antagonists

INTRODUCTION

The discovery of the role of the calcitonin gene-related peptide (CGPR) in migraine pathogenesis ushered in a new era in headache medicine. This evidence led to the development of small-molecule CGRP receptor antagonists and monoclonal antibodies targeting either CGRP or its receptor.

AREAS COVERED

We will present selected aspects of the role of CGRP in the pathogenesis of migraine, the efficacy of CGRP-targeted treatment, and the still-open questions regarding the practical application of CGRP antagonists in headache medicine.

EXPERT OPINION

CGRP-targeting drugs represent a transformative approach to migraine treatment, offering superior efficacy and tolerability compared to traditional therapies, they are a helpful addition to the treatment arsenal but also have their flaws and require further observation. Their availability provides new hope for migraine patients, particularly those who have not responded adequately to conventional treatments. Future directions for migraine care planning, especially for chronic migraine and medication-overuse headache, should include universal access to these specific and effective forms of therapy to prevent complications from the disease and its negative effects in many aspects of a patient's life.

Metabolic Pathophysiology of Cortical Spreading Depression: A Review

Cortical spreading depression (CSD) is an electrophysiologic pathological state in which a wave of depolarization in the cerebral cortex is followed by the suppression of spontaneous neuronal activity. This transient spread of neuronal depolarization on the surface of the cortex is the hallmark of CSD. Numerous investigations have demonstrated that transmembrane ion transport, astrocytic ion clearing and fatigue, glucose metabolism, the presence of certain genetic markers, point mutations, and the expression of the enzyme responsible for the production of various arachidonic acid derivatives that participate in the inflammatory response, namely, cyclooxygenase (COX), all influence CSD. Here, we explore the associations between CSD occurrence in the cortex and various factors, including how CSD is related to migraines, how the glucose state affects CSD, the effect of TBI and its relationship with CSD and glucose metabolism, how different markers can be measured to determine the severity of CSD, and possible connections to oligemia, orexin, and leptin.

Interplay between cannabinoids and the neuroimmune system in migraine

Migraine is a common and complex neurological disorder that has a high impact on quality of life. Recent advances with drugs that target the neuropeptide calcitonin gene-related peptide (CGRP) have helped, but treatment options remain insufficient. CGRP is released from trigeminal sensory fibers and contributes to peripheral sensitization, perhaps in part due to actions on immune cells in the trigeminovascular system. In this review, we will discuss the potential of cannabinoid targeting of immune cells as an innovative therapeutic target for migraine treatment. We will cover endogenous endocannabinoids, plant-derived phytocannabinoids and synthetically derived cannabinoids. The focus will be on six types of immune cells known to express multiple cannabinoid receptors: macrophages, monocytes, mast cells, dendritic cells, B cells, and T cells. These cells also contain receptors for CGRP and as such, cannabinoids might potentially modulate the efficacy of current CGRP-targeting drugs. Unfortunately, to date most studies on cannabinoids and immune cells have relied on cell cultures and only a single preclinical study has tested cannabinoid actions on immune cells in a migraine model. Encouragingly, in that study a synthetically created stable chiral analog of an endocannabinoid reduced meningeal mast cell degranulation. Likewise, clinical trials evaluating the safety and efficacy of cannabinoid-based therapies for migraine patients have been limited but are encouraging. Thus, the field is at its infancy and there are significant gaps in our understanding of the impact of cannabinoids on immune cells in migraine. Future research exploring the interactions between cannabinoids and immune cells could lead to more targeted and effective migraine treatments.

Understanding Headaches Attributed to Cranial and/or Cervical Vascular Disorders: Insights and Challenges for Neurologists

In recent decades, cranial and cervical vascular disorders have become major global health concerns, significantly impacting patients, families, and societies. Headache is a prevalent symptom of these vascular diseases and can often be the initial, primary, or sole manifestation. The intricate relationship between headaches and cranial/cervical vascular disorders poses a diagnostic and therapeutic challenge, with the underlying mechanisms remaining largely elusive. Understanding this association is crucial for the early diagnosis, prevention, and intervention of such conditions. This review aims to provide a comprehensive overview of the clinical features and potential pathogenesis of headaches attributed to cranial and cervical vascular disorders and provide a reference for disease management and a basis for potential pathological mechanisms.

Trigeminal cervical complex: A neural network affecting the head and neck

OBJECTIVES

To introduce the trigeminal cervical complex (TCC) as a comprehensive framework for understanding the anatomical and functional scope of the afferences and efferences of the trigeminal nerve and explaining common otolaryngologic symptoms, including head and neck myofascial pain syndrome. Additionally, it explores how the bidirectional transmission of neurotransmitters contributes to the sensitization of the TCC and motor nuclei.

METHODS

The study was conducted as a narrative review. The authors performed a comprehensive search of multiple databases, including Medline/OVID, Embase, Scopus, and PubMed, covering publications from inception until August 2023. Both keywords and medical subject headings related to the TCC were utilized in the search. Information from 66 studies was extracted based on predetermined inclusion and exclusion criteria.

RESULTS

This review discusses the multiple afferent connections from cranial nerves, specifically VII, IX, X, and XI, to the TCC, and their respective efferent pathways. These connections may explain various clinical manifestations in the head and neck that cannot be attributed to other medical conditions. Additionally, the review highlights the dual sensory and motor nature of cranial nerves, emphasizing the bidirectional transmission of neurotransmitters in head and neck areas, which leads to the sensitization of both the TCC and motor nuclei innervating the cervicofacial muscles.

CONCLUSION

The authors hypothesize that the central and peripheral sensitization and the intricate connections of the TCC can elucidate the pathophysiology of conditions such as otalgia, tinnitus, hearing loss, vertigo, headache, cervicogenic dizziness, bruxism, and other symptoms affecting the head and neck.

Acupuncture Treatment for Chronic Post-Traumatic Headache in Individuals with Mild Traumatic Brain Injury: A Pilot Study

Chronic post-traumatic headache (CPTH) after a mild traumatic brain injury (mTBI) has been reported in up to 60% of patients and can be extremely debilitating. While pharmacological treatments are typically used for CPTH, they frequently cause side effects and have limited effectiveness, leading individuals with CPTH to be unsatisfied with current treatment options and to seek nonpharmacological options. Acupuncture has been identified as a potential treatment option; however, the evidence in this population remains limited. The overall goal of this study was to examine the effect of a once weekly (e.g., low dose) versus twice weekly (e.g., high dose) of acupuncture treatment on CPTH in individuals with mTBI. Thirty-eight individuals were randomized to receive either 5 or 10 acupuncture treatments using a standard protocol over 5 weeks. The protocol consisted of 14 points using traditional acupuncture and 4 points using electroacupuncture. Headache outcomes, safety, treatment adherence, sleep quality, and quality of life (QOL) were assessed. The results showed that while there were no differences between dose groups for any of the outcomes assessed, acupuncture significantly reduced the number of headache days and headache pain intensity in individuals with CPTH. There were no significant changes in acute medication use or sleep quality. While there were some QOL improvements identified, these results should be interpreted with caution. Overall, acupuncture was shown to be safe and well-tolerated in people with CPTH after mTBI, and five acupuncture treatments using a standardized protocol shows promise in providing headache relief for this population.

Orofacial Pain

OBJECTIVE

This article explores the multiple etiologies, diagnosis, and management of orofacial pain.

LATEST DEVELOPMENTS

Published in 2019, the International Classification of Orofacial Pain has become the internationally accepted classification system for primary and secondary facial pain. New discoveries in temporomandibular disorders have demonstrated that they are far more complex than the traditional dental mechanistic point of view. A 2020 consensus report released by the National Academies of Sciences, Engineering, and Medicine entitled "Temporomandibular Disorders: Priorities for Research and Care" highlighted this paradigm shift and its importance for patient care, education, and research.

ESSENTIAL POINTS

Orofacial pain comprises many disorders with different etiologies and pathophysiologies. The subjectivity of the pain experience and the interrelated anatomy and physiology of the craniofacial area add to the complexity of diagnosis when the source and etiology of pain are not clear. As orofacial pain straddles the expertise of multiple disciplines, a multidisciplinary approach combining medication, physical therapy, and procedural and psychological strategies is essential in treating patients with orofacial pain.

Principles of Pain Management

OBJECTIVE

This article introduces the general principles of assessing, diagnosing, and managing pain relevant to neurologic practice.

LATEST DEVELOPMENTS

Scientific understanding of and clinical practices related to pain and pain management are advancing. The field is remarkable for the diversity of health professions engaged in this effort, including physicians, scientists, psychologists, pharmacists, and many others. Pain classification is transforming with pending changes to the International Classification of Diseases diagnostic coding system, and pain assessment has moved toward consistent application of the biopsychosocial model. The diagnosis of pain has continued to become more sophisticated with the development of additional testing modalities, clearer classification systems, and diagnostic criteria. Pain management requires both pharmacologic and nonpharmacologic elements; systematic review evidence for both of these and interventional and surgical management are increasingly available. The context of treatment remains important given the impact of social determinants of health and limitations of access to diagnostic and treatment resources. Due to global and interprofessional collaborations as well as new research funding, the outlook is positive.

ESSENTIAL POINTS

Pain is a protean experience for humans; functional MRI (fMRI) and other research modalities show that pain perception is highly multifocal, and modulation occurs at many nervous system levels. Neurologists bring special skills to pain evaluation and management, are well equipped to appreciate both the focal and diffuse nature of pain, and can envision how pain attenuates sleep, cognitive function, mobility, motivation, and social connection. By operationalizing expert knowledge of the nervous system, implementing relevant therapies, and collaborating with diverse health professions to manage pain, neurologists can succeed at and find meaning in optimizing patient outcomes.

Insights from triggers and prodromal symptoms on how migraine attacks start: The threshold hypothesis

BACKGROUND

The prodrome or premonitory phase is the initial phase of a migraine attack, and it is considered as a symptomatic phase in which prodromal symptoms may occur. There is evidence that attacks start 24-48 hours before the headache phase. Individuals with migraine also report several potential triggers for their attacks, which may be mistaken for premonitory symptoms and hinder migraine research.

METHODS

This review aims to summarize published studies that describe contributions to understanding the fine difference between prodromal/premonitory symptoms and triggers, give insights for research, and propose a way forward to study these phenomena. We finally aim to formulate a theory to unify migraine triggers and prodromal symptoms. For this purpose, a comprehensive narrative review of the published literature on clinical, neurophysiological and imaging evidence on migraine prodromal symptoms and triggers was conducted using the PubMed database.

RESULTS

Brain activity and network connectivity changes occur during the prodromal phase. These changes give rise to prodromal/premonitory symptoms in some individuals, which may be falsely interpreted as triggers at the same time as representing the early manifestation of the beginning of the attack. By contrast, certain migraine triggers, such as stress, hormone changes or sleep deprivation, acting as a catalyst in reducing the migraine threshold, might facilitate these changes and increase the chances of a migraine attack. Migraine triggers and prodromal/premonitory symptoms can be confused and have an intertwined relationship with the hypothalamus as the central hub for integrating external and internal body signals.

CONCLUSIONS

Differentiating migraine triggers and prodromal symptoms is crucial for shedding light on migraine pathophysiology and improve migraine management.

Mass balance and pharmacokinetic characterization of zavegepant in healthy male subjects

Zavegepant, a high-affinity, selective, small-molecule calcitonin gene-related peptide receptor antagonist, is approved as a nasal spray for acute treatment of migraine in adults. This phase I, open-label, single-center, single-period, nonrandomized study in six healthy male subjects assessed mass balance recovery after a single 15-min intravenous (IV) infusion dose of carbon-14 ([14C])-zavegepant. Blood, urine, and fecal samples were collected over 192 h for analysis of zavegepant in plasma and urine; total radioactivity (TR) in plasma, whole blood, urine, and feces; and zavegepant metabolite profiling and structural identification in plasma, urine, and feces. An average of 96.6% of radioactivity administered was recovered in excreta. Most TR (mean 84.9%) was recovered in the feces, indicating that biliary/fecal elimination was the main route. Volume of distribution of zavegepant based on the terminal phase (129 L) was higher than total body water (42 L), indicating substantial distribution into tissue. Total plasma clearance of zavegepant (220 mL/min) is identical to whole blood clearance given the blood/plasma partition ratio of 1, lower than typical hepatic blood flow (1450 mL/min). The observed plasma terminal half-life of zavegepant was 6.8 h. Exposure to zavegepant accounted for ~90% of circulating plasma TR, suggesting that very low levels of uncharacterized circulating metabolites were present. Metabolite profiling did not identify any metabolites representing ≥10% of radioactivity in plasma, urine, or feces. A single IV infusion of 5 mg [14C]-zavegepant was well tolerated in healthy male subjects. Disposition findings of IV [14C]-zavegepant are applicable to the disposition of the approved zavegepant nasal spray.

Prevalence of Migraine Headache among Patients with Allergic Rhinitis in a Tertiary Care Hospital, Puducherry

Allergic rhinitis is one of the most common and undertreated diseases in the world. In recent times, there has been increased development of non-sinus headaches among patients with allergic rhinitis. Various common endogenous molecules such as nitric oxide, calcitonin gene-related peptide, and histamine have been implicated in the development of migraines, which leads to the development of migraines among allergic rhinitis patients. The study aims to determine the prevalence of migraine among allergic rhinitis patients and to find the association between the various demographic factors and the presence of migraine. This cross-sectional study was conducted in the ENT department of a tertiary care hospital in Puducherry. All patients aged more than 18 years old with the symptoms of allergic rhinitis were included in the study. The study was conducted six months, from July 2023 to December 2023. ARIA classification is used to determine the severity of the allergic rhinitis, and, per International criteria for headache, was used to diagnose migraine. A total of 282 patients with allergic rhinitis participated in the study. The mean age of the patients was found to be 38.89 ± 11.04 years. The prevalence of migraine among allergic rhinitis patients was found to be 69.1%-Economic status (39.4%). About 16.7% of the patients with diabetes were associated with migraine. The study showed a significant association between sex (p-0.006), age (p < 0.001), and socio-economic status (p-0.034) with the presence of migraine. The study also showed a significant association between the severity of allergic rhinitis and the presence of migraine (p-0.034) and the type of migraine (p-0.004). The study concludes that a significant proportion of the patients with allergic rhinitis were associated with migraine. So, clinicians should always screen for the presence of the migraine in all patients with allergic rhinitis to improve the patient's quality of life.

The influence of pharmacodynamics and pharmacokinetics on the antimigraine efficacy and safety of novel anti-CGRPergic pharmacotherapies: a narrative review

INTRODUCTION

Migraine is a complex disorder, and its etiology is not yet fully understood. In the last 40 years, calcitonin gene-related peptide (CGRP) has been central to the understanding of migraine pathophysiology, leading to the development of new molecules targeting the CGRPergic system. These new molecules, such as gepants and monoclonal antibodies, are effective, well-tolerated, and safe, and are approved for clinical use.

AREAS COVERED

By searching multiple electronic scientific databases, this narrative review examined: (i) the role of CGRP in migraine; and (ii) the current knowledge on the effects of CGRPergic antimigraine pharmacotherapies, including a brief analysis of their pharmacodynamic and pharmacokinetic characteristics.

EXPERT OPINION

Current anti-CGRPergic medications, although effective, have limitations, such as side effects and lack of antimigraine efficacy in some patients. The existence of patients with medication-resistant migraine may be due to the: (i) complex migraine pathophysiology, in which several systems appear to be deregulated before, during, and after a migraine attack; and (ii) pharmacodynamic and pharmacokinetic properties of antimigraine medications. As envisioned here, although seminal studies support the notion that CGRP plays a key role in migraine headache, the dysfunction of CGRPergic transmission does not seem to be relevant in all cases.

1H-MRS reveals abnormal energy metabolism and excitatory-inhibitory imbalance in a chronic migraine-like state induced by nitroglycerin in mice

BACKGROUND

Chronic migraine is closely related to the dysregulation of neurochemical substances in the brain, with metabolic imbalance being one of the proposed causes of chronic migraine. This study aims to evaluate the metabolic changes between energy metabolism and excitatory and inhibitory neurotransmitters in key brain regions of mice with chronic migraine-like state and to uncover the dysfunctional pathways of migraine.

METHODS

A chronic migraine-like state mouse model was established by repeated administration of nitroglycerin (NTG). We used von Frey filaments to assess the mechanical thresholds of the hind paw and periorbital in wild-type and familial hemiplegic migraine type 2 mice. After the experiments, tissue was collected from five brain regions: the somatosensory cortex (SSP), hippocampus, thalamus (TH), hypothalamus, and the spinal trigeminal nucleus caudalis (TNC). Proton magnetic resonance spectroscopy (1H-MRS) was employed to study the changes in brain metabolites associated with migraine, aiming to explore the mechanisms underlying metabolic imbalance in chronic migraine-like state.

RESULTS

In NTG-induced chronic migraine-like state model, we observed a significant reduction in energy metabolism during central sensitization, an increase in excitatory neurotransmitters such as glutamate, and a tendency for inhibitory neurotransmitters like GABA to decrease. The TNC and thalamus were the most affected regions. Furthermore, the consistency of N-acetylaspartate levels highlighted the importance of the TNC-TH-SSP pathway in the ascending nociceptive transmission of migraine.

CONCLUSION

Abnormal energy metabolism and neurotransmitter imbalance in the brain region of NTG-induced chronic migraine-like state model are crucial mechanisms contributing to the chronicity of migraine.

Orofacial Migraine-A Narrative Review

The diagnosis of migraine is based on clear criteria outlined in the International Classification of Headache Disorders version 3 (ICHD-3). Notably, the criteria in ICHD-3 omit the location of the migraine. There are increasing reports of migraine in the facial region. Facial presentations of migraine are not easy to diagnose as they appear in the lower two-thirds of the face, often in the maxillary sinus region, around the ear, the upper/lower jaws, and the teeth. Additionally, a similar but distinct entity, neurovascular orofacial pain, has been established. The symptomatology of facial presentations of these headaches often resembles sinusitis and dental pathology. We will review these presentations, their diagnosis, and possible pathophysiology.

Meningeal brain borders and migraine headache genesis

Migraine is a highly prevalent and disabling pain disorder that affects >1 billion people worldwide. One central hypothesis points to the cranial meninges as a key site underlying migraine headache genesis through complex interplay between meningeal sensory nerves, blood vessels, and adjacent immune cells. How these interactions might generate migraine headaches remains incompletely understood and a subject of much debate. In this review we discuss clinical and preclinical evidence supporting the concept that meningeal sterile inflammation, involving neurovascular and neuroimmune interactions, underlies migraine headache genesis. We examine downstream signaling pathways implicated in the development of migraine pain in response to exogenous events such as infusing migraine-triggering chemical substances. We further discuss cortex-to-meninges signaling pathways that could underlie migraine pain in response to endogenous events, such as cortical spreading depolarization (CSD), and explore future directions for the field.

Patients' Experiences During the Long Journey Before Initiating Migraine Prevention with a Calcitonin Gene-Related Peptide (CGRP) Monoclonal Antibody (mAb)

INTRODUCTION

Migraine is under-diagnosed and under-treated. Many people with migraine do not seek medical care, and those who do may initially receive a different diagnosis and/or be dissatisfied with provided care on their journey before treatment with a CGRP-mAb (calcitonin-gene-related-peptide monoclonal antibody).

METHODS

This is a cross-sectional, self-reported, online survey of subjects in Lilly's Emgality® Patient Support Program in 2022. Questionnaires collected insights into subjects' prior experiences with migraine and interactions with healthcare professionals before receiving CGRP-mAbs.

RESULTS

Of the 250 participants with episodic and 250 with chronic migraine, 90% were female and white with a mean age of 26.2 years (± 11.9) at diagnosis and 40.6 (± 12.0) years at survey enrollment. Many participants (71%) suspected they had migraine before diagnosis, with 31% reluctant to seek help. Of these, approximately one-third were unaware of treatment, did not think that a physician could do anything more for migraine, would not take them seriously, or were reluctant due to a previous unhelpful experience. Participants mainly received information from friends/family (47%) or the internet (28%). Participants initially sought treatment due to an increase in migraine frequency (77%), attacks interfering with work or school (75%), or increased pain intensity (74%). Subjects saw a mean of 4.1 (± 4.3) healthcare providers before migraine diagnosis, and 20% of participants previously received a different diagnosis. Participants reported migraine causes included stress/anxiety/depression (42%), hormonal changes (30%), nutrition (20%), and weather (16%). Acute treatment of migraine included prescription (82%) and over-the-counter (50%) medications, changes in nutrition (62%), adjusting fluid intake (56%), and relaxation techniques (55%). Preventive medications included anticonvulsants (61%), antidepressants (44%), blood pressure-lowering medications (43%), and botulinum toxin A injections (17%). Most discontinuations were due to lack of efficacy or side effects.

CONCLUSION

People with migraine describe reluctance in seeking health care, and misunderstandings seem common especially in the beginning of their migraine journey. Graphical abstract available for this article.

Redefining migraine prevention: early treatment with anti-CGRP monoclonal antibodies enhances response in the real world

BACKGROUND

Anti-CGRP monoclonal antibodies (anti-CGRP MAbs) are approved and available treatments for migraine prevention. Patients do not respond alike and many countries have reimbursement policies, which hinder treatments to those who might respond. This study aimed to investigate clinical factors associated with good and excellent response to anti-CGRP MAbs at 6 months.

METHODS

European multicentre, prospective, real-world study, including high-frequency episodic or chronic migraine (CM) patients treated since March 2018 with anti-CGRP MAbs. We defined good and excellent responses as ≥50% and ≥75% reduction in monthly headache days (MHD) at 6 months, respectively. Generalised mixed-effect regression models (GLMMs) were used to identify variables independently associated with treatment response.

RESULTS

Of the 5818 included patients, 82.3% were females and the median age was 48.0 (40.0-55.0) years. At baseline, the median of MHD was 20.0 (14.0-28.0) days/months and 72.2% had a diagnosis of CM. At 6 months (n=4963), 56.5% (2804/4963) were good responders and 26.7% (1324/4963) were excellent responders. In the GLMM model, older age (1.08 (95% CI 1.02 to 1.15), p=0.016), the presence of unilateral pain (1.39 (95% CI 1.21 to 1.60), p<0.001), the absence of depression (0.840 (95% CI 0.731 to 0.966), p=0.014), less monthly migraine days (0.923 (95% CI 0.862 to 0.989), p=0.023) and lower Migraine Disability Assessment at baseline (0.874 (95% CI 0.819 to 0.932), p<0.001) were predictors of good response (AUC of 0.648 (95% CI 0.616 to 0.680)). These variables were also significant predictors of excellent response (AUC of 0.691 (95% CI 0.651 to 0.731)). Sex was not significant in the GLMM models.

CONCLUSIONS

This is the largest real-world study of migraine patients treated with anti-CGRP MAbs. It provides evidence that higher migraine frequency and greater disability at baseline reduce the likelihood of responding to anti-CGRP MAbs, informing physicians and policy-makers on the need for an earlier treatment in order to offer the best chance of treatment success.

Real-World Evidence of the Safety and Effectiveness of Atogepant Added to OnabotulinumtoxinA for the Preventive Treatment of Chronic Migraine: A Retrospective Chart Review

INTRODUCTION

Combination use of atogepant and onabotulinumtoxinA has the potential to be more effective than either alone for the preventive treatment of chronic migraine (CM) due to their complementary mechanisms of action. This analysis collected real-world data to evaluate the safety, tolerability, and effectiveness of adding atogepant to onabotulinumtoxinA as a combination preventive treatment for CM.

METHODS

This retrospective, longitudinal, multicenter chart review included adults with CM who received ≥ 2 consecutive cycles of onabotulinumtoxinA before ≥ 1 month of onabotulinumtoxinA and atogepant combination treatment. Charts at atogepant prescription (index date) and two subsequent onabotulinumtoxinA treatment visits (~ 3 and ~ 6 months post-index) were reviewed for change from baseline in monthly headache days (MHDs), ≥ 50% reduction in MHDs, discontinuation rates, and adverse events (AEs).

RESULTS

Of the 55 charts that met safety analysis criteria, 31 had data on headache days at index and first post-index visit and were eligible for effectiveness analysis (mean age 46.7 years, 94.5% female). For those with data available prior to onabotulinumtoxinA treatment (n = 25), the mean MHD was 24.0 days, reduced by 8.15 days after onabotulinumtoxinA treatment. After atogepant was added, MHD was incrementally reduced by 4.53 days and 8.75 days from index date to the first (N = 31) and second (N = 23) post-index onabotulinumtoxinA treatment visit, respectively. A ≥ 50% reduction in MHDs was achieved by 45.2% of patients ~ 3 months post-index. Atogepant and onabotulinumtoxinA were discontinued by 16.1% and 6.5% of patients, respectively. In the safety population, 32.7% of patients experienced ≥ 1 AE. No serious AEs were reported.

CONCLUSIONS

This real-world study of patients with CM demonstrated that adding atogepant to onabotulinumtoxinA as a combination preventive treatment for CM was effective by providing an additional reduction in MHDs over ~ 3 and ~ 6 months of combination treatment. Safety results were consistent with the known safety profiles of onabotulinumtoxinA and atogepant, with no new safety signals identified.

Mechanism of Traditional Chinese Medicine in Treating Migraine: A Comprehensive Review

Migraine is a common neurological illness that causes a great burden on individuals and society. Many migraine patients seek relief through complementary and alternative therapies, with Traditional Chinese medicine (TCM) often being their preferred choice. Acupuncture, Chinese herbal medicine, and massage are important components of TCM, and are commonly used in clinical treatment of migraine. This review aims to consolidate the current knowledge regarding the mechanisms of the three TCM interventions for migraine: acupuncture, herbs, and massage, and how they relieve pain. However, the mechanisms underlying the effectiveness of TCM therapies in treating migraine remain unclear. Therefore, we reviewed the research progress on acupuncture, herbal medicine, and massage as TCM approaches for the treatment of migraine. We conducted a comprehensive search of CNKI, PubMed, Web of Science, and Cochrane databases using keywords such as migraine, acupuncture, needle, herbs, herbal, prescription, decoction, massage, Tuina, and TCM, covering the period from 2000 to 2023. The literature included in the review was selected based on specified exclusion criteria. We discussed the mechanism of TCM therapies on migraine from the perspective of modern medicine, focusing on changes in inflammatory factors, neurotransmitters, and other relevant biomarkers. TCM can relieve migraine by decreasing neuropeptide levels, inhibiting inflammation, modulating neuronal sensitization, changing brain function and structure, changing blood brain barrier permeability, regulating hormone levels, and relieving muscle tension. The purpose of this paper is to provide a basis for improving the clinical strategies of TCM for the treatment of migraine.

vHIT and fHIT in Patients With Migraine, Vestibular Migraine, and Persistent Postural-Perceptual Dizziness

OBJECTIVE

Impairment in the integration of different vestibular stimuli is the proposed mechanisms in vestibular migraine (VM). In this study, it was aimed to assess the vestibulo-ocular reflex (VOR) and dynamic visual acuity (DVA) in patients with VM and to compare the results with migraine without vestibular symptoms (MwoV), and persistent postural-perceptual dizziness (PPPD) to find out if there are discriminative differences and search for a correlation with the levels of anxiety.

METHODS

Twenty-two patients with MwoV, 23 patients with VM, 22 patients with PPPD, and 23 healthy controls (HC) were studied. Video head impulse test (vHIT) and functional head impulse test (fHIT) without and with an optokinetic background (OB) were performed. Percentage of correctly identified optotypes (CA%) was considered for the fHIT test. Beck anxiety inventory (BAI) was used to assess anxiety.

RESULTS

Lateral canal vHIT gain of the patient groups were not different from the healthy controls (p > 0.05). fHIT and fHIT/OB CA% results of all patient groups were lower than the HC (p < 0.005), and VM patients had the lowest scores for both tests. BAI scores of the PPPD patients were the highest and a correlation between anxiety levels, and fHIT results could not be identified (p > 0.05).

CONCLUSION

Prominent CA% drop by the use of an OB was the main finding in patients with VM. This discriminative feature was not correlated with anxiety scores. Difficulty in resolving the conflict between visual and vestibular inputs seem to be the underlying mechanism.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Resting-state electroencephalography and magnetoencephalography in migraine-a systematic review and meta-analysis

Magnetoencephalography/electroencephalography (M/EEG) can provide insights into migraine pathophysiology and help develop clinically valuable biomarkers. To integrate and summarize the existing evidence on changes in brain function in migraine, we performed a systematic review and meta-analysis (PROSPERO CRD42021272622) of resting-state M/EEG findings in migraine. We included 27 studies after searching MEDLINE, Web of Science Core Collection, and EMBASE. Risk of bias was assessed using a modified Newcastle-Ottawa Scale. Semi-quantitative analysis was conducted by vote counting, and meta-analyses of M/EEG differences between people with migraine and healthy participants were performed using random-effects models. In people with migraine during the interictal phase, meta-analysis revealed higher power of brain activity at theta frequencies (3-8 Hz) than in healthy participants. Furthermore, we found evidence for lower alpha and beta connectivity in people with migraine in the interictal phase. No associations between M/EEG features and disease severity were observed. Moreover, some evidence for higher delta and beta power in the premonitory compared to the interictal phase was found. Strongest risk of bias of included studies arose from a lack of controlling for comorbidities and non-automatized or non-blinded M/EEG assessments. These findings can guide future M/EEG studies on migraine pathophysiology and brain-based biomarkers, which should consider comorbidities and aim for standardized, collaborative approaches.

Dietary inflammatory potential and severe headache or migraine: a systematic review of observational studies

OBJECTIVES

We conducted the current systematic review to investigate the association between dietary inflammatory index (DII) and severe headaches or migraine among adults via synthesizing observational evidence.

METHOD

We conducted a systematic literature search of observational studies through PubMed, Scopus, and Web of Science databases from inception until July 2024. The PECO framework was implemented to select eligible studies as follows: Population (adults with severe headache or migraine), Exposure (individuals with the highest adherence to a pro-inflammatory diet), Comparison (individuals with the lowest adherence to a pro-inflammatory diet), Outcome (risk of developing severe headache or migraine, headaches frequency, duration, severity, and migraine-related disability).

RESULTS

After reviewing six studies involving 31,958 individuals, we found that following an anti-inflammatory diet is associated with a lower frequency and severity of migraine headaches. Additionally, our research revealed that individuals with migraines tend to have lower adherence to an anti-inflammatory diet when compared to people without migraines. Surprisingly, adherence to a pro-inflammatory diet was linked to a reduced risk of chronic daily headaches.

CONCLUSION

Present findings imply a negative link between an inflammatory diet and severe headaches or migraine. However, further well-designed longitudinal studies are needed to interpret the causality and shed light on the underlying mechanisms.

Unravelling Migraine Stigma: A Comprehensive Review of Its Impact and Strategies for Change

Migraine-related stigma is a pervasive issue impacting nearly half of chronic migraine patients, with significant consequences for their quality of life, disability and mental health. Despite its profound effects, migraine stigma remains under-recognised in both clinical practice and research. This narrative review explores the three primary types of stigmas affecting migraine patients: public, structural and internalised. Public stigma involves negative societal attitudes and stereotypes that trivialise the condition. Structural stigma is reflected in policies that restrict access to necessary care and resources. Internalised stigma occurs when patients absorb these negative views, leading to self-blame and diminished self-worth. Addressing these different types of stigmas is crucial for improving the understanding, diagnosis and treatment of migraine. Educational efforts, advocacy and policy reform are essential strategies in this context. A deep understanding of stigma is vital for developing effective interventions that enhance clinical management and patient quality of life. Ultimately, reducing stigma can lead to better health outcomes and a more comprehensive approach to migraine care.

Dietary supplementation with grape seed extract from Vitus vinifera prevents suppression of GABAergic protein expression in female Sprague Dawley trigeminal ganglion in a model of chronic temporomandibular joint disorder

OBJECTIVE

To investigate cellular changes in protein expression in the trigeminal ganglion in an established preclinical chronic model of temporomandibular joint disorder (TMD) in response to grape seed extract (GSE) supplementation based on its beneficial use in preclinical chronic orofacial pain models.

DESIGN

Three experimental conditions included female Sprague-Dawley rats as naïve controls, and animals subjected to neck muscle inflammation and prolonged jaw opening with and without daily supplementation of GSE in the drinking water prior to inflammation. Changes were evaluated in mechanical sensitivity to von Frey filaments and protein expression in the trigeminal ganglion of animals 14 days post jaw opening.

RESULTS

Calcitonin-gene related peptide and protein kinase A, proteins positively associated with peripheral sensitization and enhanced nociception, did not show elevated expression at day 14 in the model compared to naïve or GSE supplemented animals. However, neuronal levels of glutamate decarboxylase (GAD) 65/67, which are enzymes responsible for the synthesis of the inhibitory neurotransmitter GABA that functions to suppress neuronal excitability, were significantly decreased on day 14 post jaw opening. Similarly, a significant decrease in neuronal expression of the GABA receptor subunits GABAB1 and GABAB2, but not GABAA, was observed in the TMD model. Importantly, GSE prevented suppression of GAD 65/67 and GABAB subunits, maintaining levels similar to naïve animals.

CONCLUSION

Results from our study provide evidence of the downregulation of inhibitory GABAergic proteins in trigeminal ganglion neurons in a preclinical chronic TMD model and the benefits of GSE supplementation in preventing their suppression and maintaining normal levels.

Cardiovascular safety of dihydroergotamine mesylate delivered by precision olfactory delivery (INP104) for the acute treatment of migraine

OBJECTIVE

To report the cardiovascular (CV) safety of dihydroergotamine mesylate (DHE) administered by precision olfactory delivery (INP104) from two clinical trials.

BACKGROUND

Although the absolute risk is low, migraine is associated with an increased risk of CV events. DHE is a highly effective acute treatment for migraine, but due to its theoretical risk of promoting arterial vasoconstriction, DHE is contraindicated in patients with CV disease or an unfavorable risk factor profile. The INP104 is a novel drug-device combination product approved for acute treatment of migraine that delivers DHE to the upper nasal space using precision olfactory delivery (POD®).

METHODS

The STOP 101 was a Phase 1 open-label study that assessed the safety, tolerability, and bioavailability of INP104 1.45 mg, intravenous DHE 1.0 mg, and MIGRANAL (nasal DHE) 2.0 mg in healthy participants. The STOP 301 was a pivotal Phase 3, open-label study that assessed the safety, tolerability, and exploratory efficacy of INP104 1.45 mg over 24 and 52 weeks in patients with migraine. In both studies, active or a history of CV disease, as well as significant CV risk factors, were exclusion criteria.

RESULTS

In STOP 101, 36 participants received one or more doses of investigational product. Treatment with intravenous DHE, but not INP104 or nasal DHE, resulted in clinically relevant changes from baseline in systolic blood pressure (BP; 11.4 mmHg, 95% confidence interval [CI] 7.9-15.0) and diastolic BP (13.3 mmHg, 95% CI 9.4-17.1) at 5 min post-dose, persisting up to 30 min post-dose for systolic BP (6.3 mmHg; 95% CI 3.0-9.5) and diastolic BP (7.9 mmHg, 95% CI 3.9-11.9). None of the treatments produced any clinically meaningful electrocardiogram (ECG) changes. In STOP 301, 354 patients received one or more doses of INP104. Over 24 weeks, five patients (1.4%) experienced a non-serious, vascular treatment-emergent adverse event (TEAE). Minimal changes were observed for BP and ECG parameters over 24 or 52 weeks. Off-protocol concomitant use of triptans and other ergot derivatives did not result in any TEAEs.

CONCLUSION

In two separate studies, INP104 demonstrated a favorable CV safety profile when used in a study population without CV-related contraindications.

Sumatriptan-naproxen sodium in migraine: A review

BACKGROUND

Varied responses to acute migraine medications have been observed, with over one-third (34.5%) of patients reporting insufficient headache relief. Sumatriptan-naproxen sodium, a single, fixed-dose combination tablet comprising sumatriptan 85 mg and naproxen sodium 500 mg, was developed with the rationale of targeting multiple putative mechanisms involved in the pathogenesis of migraine to optimise acute migraine care.

METHODS

A narrative review of clinical trials investigating sumatriptan-naproxen sodium for both adults and adolescents was performed in March 2024.

RESULTS

Across a total of 14 clinical trials in nine publications, sumatriptan-naproxen sodium offered greater efficacy for 2-h pain freedom (14/14) and sustained pain-free response up to 24 h (13/14) compared with monotherapy and/or placebo for both adult and adolescent study participants with an acceptable and well-tolerated adverse effect profile. Clinical trial data also demonstrates the effectiveness of sumatriptan-naproxen sodium in participants with allodynia, probable migraine, menstrual-related migraine and those with poor responses to acute, non-specific, migraine medication.

CONCLUSIONS

Multi-mechanistic therapeutic agents offer an opportunity to optimise acute medications by targeting multiple mediators involved in the pathogenesis of migraine. Sumatriptan-naproxen sodium resulted in greater initial and sustained pain freedom, compared with either sumatriptan, naproxen-sodium and/or placebo, for the treatment of single or multiple attacks of migraine across both adult and adolescent study populations.

Zinc as An Emerging Therapy in the Management of Migraine: A Systematic Review

Migraine, a common neurological condition, is characterized by a chronic and recurring headache that affects numerous people globally. Several drugs are available for the treatment and prophylaxis of migraine with their shortfalls. Zinc could play a role in migraine management because of its anti-inflammatory and antioxidant properties. This study was planned to systematically review the scientific databases to gather evidence regarding the role of zinc in the management of migraine. The protocol was registered with the PROSPERO (CRD42023398478). Three databases PubMed, The Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov were searched with the keywords "migraine", "migraine disorders" and "zinc". A literature search led to the retrieval of 35 studies; of these five studies (2 clinical trials and 3 observational studies) were comprised in a systematic review. Clinical trials' risk of bias assessment is low. The review suggested a positive role of zinc in managing migraine however, the evidence requires further strengthening. The available clinical literature on the effectiveness of zinc in migraines is limited; hence, more robust and large clinical trials are required to support the role of zinc in migraines.

Iron Deficiency Anemia and Migraine: A Literature Review of the Prevalence, Pathophysiology, and Therapeutic Potential

This literature review explores the association between iron deficiency anemia and migraines, examining their prevalence, underlying pathophysiology, and therapeutic potential of iron supplementation in managing migraine symptoms. A systematic search across major academic databases, including PubMed, Google Scholar, ScienceDirect, and Science.gov, identified relevant peer-reviewed studies that focus on the link between iron deficiency anemia and migraines. The review highlights a higher prevalence of iron deficiency anemia among migraine sufferers, particularly women, with several studies indicating a significant inverse relationship between serum ferritin levels and migraine severity. The findings suggest that low iron levels may exacerbate migraine symptoms, and iron supplementation has been shown to reduce the frequency and intensity of migraines, especially in patients with confirmed iron deficiency anemia. The review also discusses the unique susceptibility of women, particularly those of reproductive age, to both iron deficiency anemia and migraines, emphasizing the importance of gender-specific approaches in treatment. Moreover, the potential impact of iron deficiency on neurovascular function and its contribution to migraine pathogenesis is explored, reinforcing the need for comprehensive management strategies that include nutritional interventions. While iron supplementation appears to be a promising therapeutic option, further research is required to fully understand its long-term effects and to refine treatment protocols to avoid the risks associated with iron overload. This review underscores the significance of addressing nutritional deficiencies as part of a holistic approach to migraine management, offering insights into potential avenues for improving patient outcomes.

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.

From the latin "re-cordis, passing through the heart": autonomic modulation differentiates migraineurs from controls when recounting a significant life event

OBJECTIVE

The literature on clinical psychophysiology highlights the possibility of using Heart Rate Variability (HRV) as an index of psychophysical balance and resilience to stress. This study investigates the differences in stress reactivity and subsequent recovery between a group of migraineurs and healthy controls.

METHODS

Socio-demographic (i.e., sex, age, profession, marital status, and level of education) and psychophysiological (HR and HRV) measures of a group of thirty subjects with migraine (26 migraineurs without aura (86.7%), 2 migraineurs with aura (6.7%), and 2 migraineurs with and without aura (6.7%)) and from thirty healthy control subjects were collected. In particular, HRV was analyzed through frequency-domain parameters, including Low-Frequency (LF; 0.04-0.15 Hz) and High-Frequency (HF; 0.15-0.4 Hz) bands as well as LF/HF ratio during a Psychophysiological Stress Profile (PSP) structured in seven phases: (1) Baseline, (2) Objective stressor 1 (Stroop Test), (3) Rest 1, (4) Objective stressor 2 (Mental Arithmetic Task), (5) Rest 2, (6) Subjective stressor (recount a significant life event), and (7) Rest 3. The LF, HF, and LF/HF ratio values were transformed into a logarithmic scale (i.e., log-LF, log-HF, and log LF/HF ratio). Additionally, LF and HF were converted into normalized units (0-100) (i.e., LF% and HF%) which, in turn, were used to obtain reactivity and recovery to stress through delta values (Δ) calculation.

RESULTS

Subjects with migraine reported greater ΔLF% levels of reactivity and recovery to subjective stressor, demonstrating a prevalence of sympathetic activity while recounting a personal life event. At the same time, a lowering of the same values was found in the subjects of the group control.

DISCUSSION

Our results underline the importance of conducting a psychophysiological assessment in patients with headaches because reduced stress management skills could influence the clinical manifestations of the disease, considering stress as one of the most common triggers for migraine patients.

Global, regional, and national burden and trends of migraine among youths and young adults aged 15-39 years from 1990 to 2021: findings from the global burden of disease study 2021

BACKGROUND

Migraine, a widespread neurological condition, substantially affects the quality of life, particularly for adolescents and young adults. While its impact is significant, there remains a paucity of comprehensive global research on the burden of migraine in younger demographics. Our study sought to elucidate the global prevalence, incidence, and disability-adjusted life-years (DALYs) associated with migraine in the 15-39 age group from 1990 to 2021, utilizing data from the Global Burden of Disease (GBD) 2021 study.

METHODS

Our comprehensive study analyzed migraine data from the GBD 2021 report, examining the prevalence, incidence, and DALYs across 204 countries and territories over a 32-year span. We stratified the information by age, sex, year, geographical region, and Socio-demographic Index (SDI). To evaluate temporal trends in these metrics, we employed the estimated annual percentage change (EAPC) calculation.

RESULTS

Between 1990 and 2021, the worldwide prevalence of migraine among 15-39 year-olds increased substantially. By 2021, an estimated 593.8 million cases were reported, representing a 39.52% rise from 425.6 million cases in 1990. Global trends showed increases in age-standardized prevalence rate, incidence rate, and DALY rate for migraine during this period. The EAPC were positive for all three metrics: 0.09 for ASPR, 0.03 for ASIR, and 0.09 for DALY rate. Regions with medium SDI reported the highest absolute numbers of prevalent cases, incident cases, and DALYs in 2021. However, high SDI regions demonstrated the most elevated rates overall. Across the globe, migraine prevalence peaked in the 35-39 age group. Notably, female rates consistently exceeded male rates across all age categories.

CONCLUSION

The global impact of migraine on youths and young adults has grown considerably from 1990 to 2021, revealing notable variations across SDI regions, countries, age groups, and sexes. This escalating burden necessitates targeted interventions and public health initiatives, especially in areas and populations disproportionately affected by migraine.

4-Phenyl-thiazole-based dual inhibitors of fatty acid amide hydrolase and soluble epoxide hydrolase do not alleviate orofacial inflammatory pain in female rats

Pain arising from trigeminal systems such as headache is common, debilitating, and current treatments (e.g., sumatriptan) are limited. New treatments that target novel mechanisms of action may be required to innovate both short- and long-term pain therapy. Fatty acid amide hydrolase and soluble epoxide hydrolase are two pain-related enzymes that regulate pain and inflammation via independent pathways. We have previously demonstrated that simultaneous inhibition of these enzymes using a novel dual inhibitor alleviates acute inflammatory pain in the hindpaw and does not depress wheel running in rats. Here, we expanded on these findings and performed structure-activity relationships of our lead compound, the 4-phenyl-thiazole-based dual inhibitor SW-17, to generate 18 analogs and tested them for their inhibition at both enzymes. Conversion of the sulfonamide group to a tertiary amine led to a general decrease in the potency for the sEH enzyme, while this change was well-tolerated at the FAAH enzyme yielding several strong inhibitors. Six selected inhibitors were evaluated in mouse and rat sEH inhibition assays and results showed a species difference, i.e. 4-phenyl-thiazole-based analogs are significantly less or not active in mouse sEH compared to human and rat enzymes. The most potent inhibitor, SW-17, was evaluated in a plasma stability assay in human and rat plasma and showed moderate stability. However, SW-17 did not alleviate orofacial inflammatory pain in female rats compared to the traditional anti-migraine agent sumatriptan. Although modification of 4-phenyl-thiazole-based dual inhibitor SW-17 changes potencies at both FAAH and sEH, these approaches may not produce antinociception against trigeminal pain. Key Words: polypharmacology, formalin, inflammation, enzyme inhibition, structure-activity relationship studies.

Voltage-gated Calcium Channels as Potential Therapeutic Targets in Migraine

Migraine is a complex and highly incapacitating neurological disorder that affects around 15% of the general population with greater incidence in women, often at the most productive age of life. Migraine physiopathology is still not fully understood, but it involves multiple mediators and events in the trigeminovascular system and the central nervous system. The identification of calcitonin gene-related peptide as a key mediator in migraine physiopathology has led to the development of effective and highly selective antimigraine therapies. However, this treatment is neither accessible nor effective for all migraine sufferers. Thus, a better understanding of migraine mechanisms and the identification of potential targets are still clearly warranted. Voltage-gated calcium channels (VGCCs) are widely distributed in the trigeminovascular system, and there is accumulating evidence of their contribution to the mechanisms associated with headache pain. Several drugs used in migraine abortive or prophylactic treatment target VGCCs, which probably contributes to their analgesic effect. This review aims to summarize the current evidence of VGGC contribution to migraine physiopathology and to discuss how current pharmacological options for migraine treatment interfere with VGGC function. PERSPECTIVE: Calcitonin gene-related peptide (CGRP) represents a major migraine mediator, but few studies have investigated the relationship between CGRP and VGCCs. CGRP release is calcium channel-dependent and VGGCs are key players in familial migraine. Further studies are needed to determine whether VGCCs are suitable molecular targets for treating migraine.

Calcitonin Gene-Related Peptide Inhibitors in the Treatment of Migraine in the Pediatric and Adolescent Populations: A Review

There are limited well-studied treatments for migraine in the pediatric population. Calcitonin gene-related peptide (CGRP) inhibitors are an established safe and effective treatment in adults, and use may be appropriate for pediatric patients in certain clinical situations. We describe migraine pathophysiology as it relates to CGRP, provide an overview of available medications, and discuss clinical usage in this population.

In search of a neuropsychological profile for migraine: A scoping review

OBJECTIVE

Migraine is commonly overlooked by the general population and by professionals in research and clinical practice. Moreover, it is difficult to grasp the neuropsychological profile of migraineurs due to the cyclic nature of the disorder. With this in mind, a scoping review of the literature was conducted with the goal of characterizing cognitive domains associated with deficits in migraine.

METHODS

PubMed, PsychInfo, Scopus, EMBASE and OpenGrey databases were searched for studies published from 1st January 2006 to 30th November 2022. Following the review process, 52 eligible studies were included in the review.

RESULTS

Studies included in this review show mixed and sometimes contradictory findings. Overall, both visual and auditory perception appear to be impaired. Deficits on attention, many memory processes, visuospatial function and spatial navigation and on a wide range of executive functions (set-shifting and cognitive flexibility, decision-making and reasoning, working memory and prospective memory) complete a complex cognitive profile in migraine. Lack of consistency across studies in sample selection and sizes, lack of detailed links between cognitive deficits and specific migraine phases, or length and chronicity, inconsistencies on the role of aura in cognitive function; and heterogeneity and sometimes questionable reliability and validity of some of the cognitive measures used may affect the clarity and consistency of results observed.

CONCLUSION

Further research properly addressing the role of gender and age, migraine stage, length and chronicity of the condition, the effect of aura and comorbidities is needed, alongside increasing consistency across diverse neuropsychological assessment protocols.

SIGNIFICANCE

This review provides a comprehensive, up-to-date picture of the current status of knowledge in relation to the characterization of the complex cognitive profile of migraine. It offers detailed information of the existing research gaps and challenges to improve the cognitive characterization of migraine across its different stages and leads clinicians to carefully consider the selection of relevant cognitive tasks, in order to grasp more accurately the patient's cognitive profile; an assessment that should be an integral part of any protocol developed for the clinical assessment and subsequent treatment planning for migraine.

Real-world experiences of migraine patients on Erenumab: a Kuwait single center cohort

BACKGROUND

Migraine is a prevalent headache disorder with a significant impact on the quality of life. This study aims to investigate the effectiveness and safety of erenumab, mAb targeting the CGRP receptor, in treating chronic (CM) and episodic (EM) migraine in clinical practice Kuwait, providing region-specific insights to treatment options.

METHOD

This was a prospective observational cohort study of patients diagnosed with EM or CM treated with erenumab. The primary outcome of the study was to assess the proportion of patients achieving ≥ 50% reduction in monthly mean migraine days, and several changes including the mean number of monthly migraine days, the frequency of analgesic use, attack severity, AEs, and QoL.

RESULTS

The study included 151 patients with a mean age of 44.0±11.4 years, and 81.9% female. The primary outcome was achieved in 74.2% of patients, with a significant (p < 0.001) reduction in headache frequency, pain severity, analgesic use, and improvement in QoL. Age and duration of migraine were significant predictors of achieving a ≥ 50% reduction in headache frequency after therapy (OR = 0.955; p = 0.009) and (OR = 0.965; p = 0.025), respectively. Treatment compliance was observed in 76.2% of patients, and 24.5% discontinued treatment. Constipation was the most commonly reported AEs (6.0%), and conservative management was the most common approach to managing AEs.

CONCLUSION

Erenumab was effective in reducing the frequency and severity of migraine attacks and improving QoL, and safe with manageable AEs in a real-world setting in Kuwait. Further research is needed to better understand erenumab's effectiveness and safety in different populations and settings, as well as to compare it with other migraine prophylactic treatments.

Exploring the anti-migraine effects of Tianshu capsule: chemical profile, metabolic behavior, and therapeutic mechanisms

BACKGROUND

Migraine is widely recognized as the third most prevalent medical condition globally. Tianshu capsule (TSC), derived from "Da Chuan Xiong Fang" of the Jin dynasty, is integral in the clinical treatment of migraine. However, the chemical properties and therapeutic mechanisms of TSC different portions remain unclear.

PURPOSE

This study was designed to investigate the effects of TSC different portions (including small molecular TSCP-SM and polysaccharides TSC-P) on migraine and explore the underlying mechanisms.

STUDY DESIGN AND METHODS

First of all, migraine rats were established by nitroglycerin injection and treated with TSC, TSC-P, and TSC-SM. ELISA, qPCR, and immunofluorescence were used to evaluate the pharmacological effects on migraine rats. Secondly, UPLC-Q/TOF-MS and GC--MS were employed to detect the components of TSC-SM. PMP-HPLC, NMR, FT-IR, UV-Vis, AFM, and SEM were used for the chemical profiling of polysaccharides. Thirdly, the metabolic behavior profile of TSC-P was characterized by oral administrated fluorescence-labeled TSC-P and detected by NIRF imaging. Finally, the anti-migraine mechanisms were explored by determining the composition of gut microbiota, analyzing colonic short-chain fatty acids (SCFAs), and examining serum tryptophan-related metabolites.

RESULTS

Both small molecules (45 volatiles and 114 small molecules) and polysaccharides (including Glc, Ara, Gal, and Gal A) have exhibited effectiveness in alleviating migraine, and this efficacy is associated with reduced CGRP and iNOS levels, along with increased β-EP expressions. Further mechanistic exploration revealed that small-molecules exhibited effectiveness in migraine treatment by exerting antioxidative actions, while polysaccharides demonstrated superior therapeutic effects in regulating 5-HT levels. By monitoring the metabolic behavior of polysaccharides with fluorescent labeling, it was observed that TSC-P exhibited poor absorption. Instead, TSC-P demonstrated its therapeutic effects by modulating the aberrations in gut microbiota (including Alloprevotella, Muribaculaceae_ge, and Ruminococcaceae_UCG-005), cecum short-chain fatty acids (such as isobutyric, isovaleric, and valeric acids), and serum tryptophan-related metabolites (including indole-3-acetamide, tryptophol, and indole-3-propionic acid).

CONCLUSION

This research provides innovative insights into chemical composition, metabolic behavior, and proposed anti-migraine mechanisms of TSC from a polarity-based perspective, and pioneering an exploration focused on the polysaccharide components within TSC for the first time.

Efficacy and safety of high-frequency repetitive transcranial magnetic stimulation (rTMS) for migraine: a meta-analysis of randomized controlled trials

OBJECTIVE

To assess the efficacy and safety of high-frequency repetitive transcranial magnetic stimulation in the prevention or treatment of migraine by conducting a pooled analysis of relevant randomized controlled trials.

METHODS

The PubMed, Embase, Cochrane, OVID, SCOPUS, Web of Science, and clinicaltrials.gov databases were systematically searched for randomized controlled trials (RCTs) comparing high-frequency rTMS and sham stimulation for the prevention or treatment of migraine. A meta-analysis of relevant outcome measures was performed using RevMan 5.3 software.

RESULTS

Eight RCTs with a total of 384 patients were included. A total of 23 patients dropped out, and thus, 361 patients were ultimately included for analysis. The high-frequency rTMS group had a lower frequency of attacks than the sham group (MD = - 5.10; 95% CI: - 8.10, - 2.09; P = 0.0009). The rTMS group has less intense headaches than the sham group (SMD = - 0.74; 95% CI - 1.04, - 0.44; P < 0.00001). High-frequency rTMS improved patient disability (SMD = - 0.45; 95% CI - 0.75, - 0.16; P = 0.003). High-frequency rTMS led to no advantage in reducing the number of abortive medications (MD = - 1.10; 95% CI - 3.28, 1.08; P = 0.32), but it increased the occurrence of adverse events (RR = 1.69; 95% CI 1.09, 2.64; P = 0.02).

CONCLUSIONS

High-frequency rTMS reduces the frequency of attacks and headache intensity in migraine patients and improves the patient's disability, but it also increases adverse events.

Instrumental assessment of pressure pain threshold over trigeminal and extra-trigeminal area in people with episodic and chronic migraine: a cross-sectional observational study

BACKGROUND

Central and peripheral sensitization are characterized by widespread hyperalgesia that is manifested by larger pain extent area and reduction in pressure pain threshold (PPT). PPT decreases in patients with migraine not only over the trigeminal cervical complex but also throughout the body.

METHODS

A cross-sectional study was adopted to assess the local and widespread hyperalgesia in chronic and episodic migraine patients respect to healthy controls. The guidelines of Andersen's were used to evaluate the PPT bilaterally over 3 muscles in the trigemino-cervical complex (temporalis, sub-occipitalis, trapezius) and over 1 muscle far from this area (tensor fasciae latae).

RESULTS

Thirty subjects with episodic migraine (35.8 ± 2.82 years), 30 with chronic migraine (53.03 ± 19.79 years), and 30 healthy controls (29.06 ± 14.03 years) were enrolled. The interaction effect was present for the trapezius muscle with a significant difference between the right and the left side in episodic group (p = 0.003). A group effect was highlighted in all four muscles analyzed such as suboccipital (p < 0.001), temporalis (p > 0.001), trapezius (p < 0.001), and TFL (p < 0.001). PPT was usually higher in the control group than in the episodic group which in turn was characterized by higher PPT values than the chronic group.

CONCLUSIONS

People with chronic and episodic migraine presented lower PPT than healthy controls both in the trigeminal and in the extra-trigeminal area. People with chronic migraine presented lower PPT than episodic migraine only in the trigeminal area. Temporalis and sub-occipitalis are the most sensitive muscles in people with chronic and episodic migraine.

Efficacy of a dual task protocol on neurophysiological and clinical outcomes in migraine: a randomized control trial

The main aim of this study was to investigate the efficacy of a dual task protocol in people with episodic migraine with respect to both active exercises only and cognitive task only treatments, concerning some neurophysiological and clinical outcomes. A randomized control trial was adopted in people with episodic migraine without aura. Some neurophysiological and clinical outcomes were collected (t0): resting motor threshold (rMT), short intracortical inhibition (SICI) and facilitation (ICF), pressure pain threshold (PPT), trail making test (TMT), frontal assessment battery (FAB), headache-related disability (MIDAS) and headache parameters. Then, participants were randomized into three groups: active exercise only (n = 10), cognitive task only (n = 10) and dual task protocol (n = 10). After 3 months of each treatment and after 1-month follow-up the same neurophysiological and clinical outcomes were revaluated. A significant time x group effect was only found for the trapezius muscle (p = 0.012, pη2 = 0.210), suggesting that PPT increased significantly only in active exercise and dual task protocol groups. A significant time effect was found for rMT (p < 0.001, pη2 = 0.473), MIDAS (p < 0.001, pη2 = 0.426), TMT (p < 0.001, pη2 = 0.338) and FAB (p < 0.001, pη2 = 0.462). A repeated measures ANOVA for SICI at 3 ms highlighted a statistically significant time effect for the dual task group (p < 0.001, pη2 = 0.629), but not for the active exercises group (p = 0.565, pη2 = 0.061), and for the cognitive training (p = 0.357, pη2 = 0.108). The dual task protocol seems to have a more evident effect on both habituation and sensitization outcomes than the two monotherapies taken alone in people with migraine.

Unraveling the interplay of neuroinflammatory signaling between parenchymal and meningeal cells in migraine headache

BACKGROUND

The initiation of migraine headaches and the involvement of neuroinflammatory signaling between parenchymal and meningeal cells remain unclear. Experimental evidence suggests that a cascade of inflammatory signaling originating from neurons may extend to the meninges, thereby inducing neurogenic inflammation and headache. This review explores the role of parenchymal inflammatory signaling in migraine headaches, drawing upon recent advancements. BODY: Studies in rodents have demonstrated that sterile meningeal inflammation can stimulate and sensitize meningeal nociceptors, culminating in headaches. The efficacy of relatively blood-brain barrier-impermeable anti-calcitonin gene-related peptide antibodies and triptans in treating migraine attacks, both with and without aura, supports the concept of migraine pain originating in meninges. Additionally, PET studies utilizing inflammation markers have revealed meningeal inflammatory activity in patients experiencing migraine with aura, particularly over the occipital cortex generating visual auras. The parenchymal neuroinflammatory signaling involving neurons, astrocytes, and microglia, which eventually extends to the meninges, can link non-homeostatic perturbations in the insensate brain to pain-sensitive meninges. Recent experimental research has brought deeper insight into parenchymal signaling mechanisms: Neuronal pannexin-1 channels act as stress sensors, initiating the inflammatory signaling by inflammasome formation and high-mobility group box-1 release in response to transient perturbations such as cortical spreading depolarization (CSD) or synaptic metabolic insufficiency caused by transcriptional changes induced by migraine triggers like sleep deprivation and stress. After a single CSD, astrocytes respond by upregulating the transcription of proinflammatory enzymes and mediators, while microglia are involved in restoring neuronal structural integrity; however, repeated CSDs may prompt microglia to adopt a pro-inflammatory state. Transcriptional changes from pro- to anti-inflammatory within 24 h may serve to dampen the inflammatory signaling. The extensive coverage of brain surface and perivascular areas by astrocyte endfeet suggests their role as an interface for transporting inflammatory mediators to the cerebrospinal fluid to contribute to meningeal nociception.

CONCLUSION

We propose that neuronal stress induced by CSD or synaptic activity-energy mismatch may initiate a parenchymal inflammatory signaling cascade, transmitted to the meninges, thereby triggering lasting headaches characteristic of migraine, with or without aura. This neuroinflammatory interplay between parenchymal and meningeal cells points to the potential for novel targets for migraine treatment and prophylaxis.

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.

The TRPA1 Ion Channel Mediates Oxidative Stress-Related Migraine Pathogenesis

Although the introduction of drugs targeting calcitonin gene-related peptide (CGRP) revolutionized migraine treatment, still a substantial proportion of migraine patients do not respond satisfactorily to such a treatment, and new therapeutic targets are needed. Therefore, molecular studies on migraine pathogenesis are justified. Oxidative stress is implicated in migraine pathogenesis, as many migraine triggers are related to the production of reactive oxygen and nitrogen species (RONS). Migraine has been proposed as a superior mechanism of the brain to face oxidative stress resulting from energetic imbalance. However, the precise mechanism behind the link between migraine and oxidative stress is not known. Nociceptive primary afferent nerve fiber endings express ion channel receptors that change harmful stimuli into electric pain signals. Transient receptor potential cation channel subfamily A member 1 (TRPA1) is an ion channel that can be activated by oxidative stress products and stimulate the release of CGRP from nerve endings. It is a transmembrane protein with ankyrin repeats and conserved cysteines in its N-terminus embedded in the cytosol. TRPA1 may be a central element of the signaling pathway from oxidative stress and NO production to CGRP release, which may play a critical role in headache induction. In this narrative review, we present information on the role of oxidative stress in migraine pathogenesis and provide arguments that TRPA1 may be "a missing link" between oxidative stress and migraine and therefore a druggable target in this disease.

Pharmacological investigation of genistein for its therapeutic potential against nitroglycerin-induced migraine headache

OBJECTIVES

Migraine, typically occurs on one side of the head, lasts for hours to days. Trigemino-vascular system (TVS) plays a vital role in pain generation, with neurogenic inflammation and oxidative stress playing key roles in its pathophysiology.

METHODS

This study aimed to investigate genistein's potential as anti-inflammatory and anti-oxidant agent in mitigating migraine pain. Genistein (20 and 50 mg/kg) was administered intraperitoneally (IP) to nitroglycerin (NTG; 10 mg/kg)-induced migraine model in rats. Behavioral analysis, antioxidant assay, immunohistochemistry (IHC), histopathological examination, ELISA, and RT-PCR were conducted to evaluate the antimigraine potential of genistein.

KEY FINDINGS

In-silico analysis showed genestien's ACE values of -4.8 to -9.2 Kcal/mol against selected protein targets. Genistein significantly reversed mechanical and thermal nociception, light phobicity, and head scratching; increased the intensities of GST, GSH, catalase; and down regulated lipid peroxidase (LPO) in cortex and trigeminal nucleus caudalis (TNC). It also reduced Nrf2, NF-kB, and IL6 expression, analyzed through IHC, improved histopathological features, and increased COX-2 and decreased PPAR-γ expressions, while RT-PCR analysis revealed increased PPAR-γ expressions in genistein-treated rats.

CONCLUSION

Genistein exhibited potent antioxidant and anti-inflammatory properties in migraine treatment, acting through multifactorial mechanisms by modulating the expression of numerous proteins in the region cortex and TNC.