The Prevalence of Premonitory Symptoms in Migraine: A Questionnaire Study in 461 Patients

Intervening in the Premonitory Phase to Prevent Migraine: Prospects for Pharmacotherapy

Migraine is a common brain condition characterised by disabling attacks of headache with sensory sensitivities. Despite increasing understanding of migraine neurobiology and the impacts of this on therapeutic developments, there remains a need for treatment options for patients underserved by currently available therapies. The first specific drugs developed to treat migraine acutely, the serotonin-5-hydroxytryptamine [5-HT1B/1D] receptor agonists (triptans), seem to require headache onset in order to have an effect, while early treatment during mild pain before headache escalation improves short-term and long-term outcomes. Some patients find treating in the early window once headache has started but not escalated difficult, and migraine can arise from sleep or in the early hours of the morning, making prompt treatment after pain onset challenging. Triptans may be deemed unsuitable for use in patients with vascular disease and in those of older age and may not be effective in a proportion of patients. Headache is also increasingly recognised as being just one of the many facets of the migraine attack, and for some patients it is not the most disabling symptom. In many patients, painless symptoms can start prior to headache onset and can reliably warn of impending headache. There is, therefore, a need to identify therapeutic targets and agents that may be used as early as possible in the course of the attack, to prevent headache onset before it starts, and to reduce both headache and non-headache related attack burden. Early small studies using domperidone, naratriptan and dihydroergotamine have suggested that this approach could be useful; these studies were methodologically less rigorous than modern day treatment studies, of small sample size, and have not since been replicated. The emergence of novel targeted migraine treatments more recently, specifically calcitonin gene-related peptide (CGRP) receptor antagonists (gepants), has reignited interest in this strategy, with encouraging results. This review summarises historical and emerging data in this area, supporting use of the premonitory phase as an opportunity to intervene as early as possible in migraine to prevent attack-related morbidity.

Models of Trigeminal Activation: Is There an Animal Model of Migraine?

Migraine, recognized as a severe headache disorder, is widely prevalent, significantly impacting the quality of life for those affected. This article aims to provide a comprehensive review of the application of animal model technologies in unraveling the pathomechanism of migraine and developing more effective therapies. It introduces a variety of animal experimental models used in migraine research, emphasizing their versatility and importance in simulating various aspects of the condition. It details the benefits arising from the utilization of these models, emphasizing their role in elucidating pain mechanisms, clarifying trigeminal activation, as well as replicating migraine symptoms and histological changes. In addition, the article consciously acknowledges the inherent limitations and challenges associated with the application of animal experimental models. Recognizing these constraints is a fundamental step toward fine-tuning and optimizing the models for a more accurate reflection of and translatability to the human environment. Overall, a detailed and comprehensive understanding of migraine animal models is crucial for navigating the complexity of the disease. These findings not only provide a deeper insight into the multifaceted nature of migraine but also serve as a foundation for developing effective therapeutic strategies that specifically address the unique challenges arising from migraine pathology.

Aeromedical Risk of Migraine

INTRODUCTION: Migraine is a common condition that can carry considerable risk to aeromedical duties. Because randomized controlled trials are not an appropriate method to evaluate flight safety risk for medical conditions that may cause subtle or sudden incapacitation, the determination of fitness-to-fly must be based on risk assessments informed by extrapolated evidence. Therefore, we conducted a review of current literature to provide background information to inform the aeromedical risk assessment of migraine using a risk matrix approach.METHODS: We identified studies on topics pertinent to conducting an aeromedical risk assessment of migraine. We generated an overview of the literature synthesizing the findings of articles retrieved from searches of Scopus, Ovid, PubMed, and the Cochrane Library published in English from all years, in both general and aircrew populations. International headache and neurology guidelines, as well as headache policies from the U.S. Air Force, were also reviewed.RESULTS: This review includes information on the following topics relevant to conducting an evidence-based risk assessment of migraine: diagnosis, prevalence, incidence, natural course, clinical presentation, triggers, comorbidities, neuroimaging, implications of family history, and efficacy of pharmacological and nonpharmacological therapies.DISCUSSION: This review summarizes current literature on migraine for use in a risk matrix approach to the aeromedical assessment of migraine in prospective and current aircrew. Awareness of the most current epidemiological data related to a variety of migraine parameters facilitates an evidence-based risk assessment of migraine in aircrew and requires iterative updates as new information becomes available.Mainland RL, Skinner CR, Saary J. Aeromedical risk of migraine. Aerosp Med Hum Perform. 2024; 95(2):101-112.

Premonitory symptoms in migraine: A REFORM Study

BACKGROUND

Estimates of proportions of people with migraine who report premonitory symptoms vary greatly among previous studies. Our aims were to establish the proportion of patients reporting premonitory symptoms and its dependency on the enquiry method. Additionally, we investigated the impact of premonitory symptoms on disease burden using Headache Impact Test (HIT-6), Migraine Disability Assessment (MIDAS) and World Health Organization Disability Assessment 2.0 (WHODAS 2.0), whilst investigating how various clinical factors influenced the likelihood of reporting premonitory symptoms.

METHODS

In a cross-sectional study, premonitory symptoms were assessed among 632 patients with migraine. Unprompted enquiry was used first, followed by a list of 17 items (prompted). Additionally, we obtained clinical characteristics through a semi-structured interview.

RESULTS

Prompted enquiry resulted in a greater proportion reporting premonitory symptoms than unprompted (69.9% vs. 43.0%; p < 0.001) and with higher symptom counts (medians 2, interquartile range = 0-6 vs. 1, interquartile range = 0-1; p < 0.001). The number of symptoms correlated weakly with HIT-6 (ρ = 0.14; p < 0.001) and WHODAS scores (ρ = 0.09; p = 0.041). Reporting postdromal symptoms or triggers increased the probability of reporting premonitory symptoms, whereas monthly migraine days decreased it.

CONCLUSIONS

The use of a standardized and optimized method for assessing premonitory symptoms is necessary to estimate their prevalence and to understand whether and how they contribute to disease burden.

Ubrogepant for the treatment of migraine attacks during the prodrome: a phase 3, multicentre, randomised, double-blind, placebo-controlled, crossover trial in the USA

BACKGROUND

Ubrogepant is a calcitonin gene-related peptide (CGRP) receptor antagonist that is approved for acute treatment of migraine. The prodrome is the earliest phase of a migraine attack and is characterised by non-aura symptoms that precede headache onset. The aim of this trial was to evaluate the efficacy, safety, and tolerability of ubrogepant 100 mg compared with placebo for the acute treatment of migraine when administered during the prodrome.

METHODS

This PRODROME trial was a phase 3, multicentre, randomised, double-blind, placebo-controlled, crossover trial of ubrogepant 100 mg conducted at 75 research centres and headache clinics in the USA. Eligible participants were adults aged 18-75 years who had at least a 1-year history of migraine with or without aura and a history of two to eight migraine attacks per month with moderate to severe headache in each of the 3 months before screening. Eligible participants were randomly assigned (1:1) to either receive placebo to treat the first qualifying prodrome event and ubrogepant 100 mg to treat the second qualifying prodrome event or to receive ubrogepant 100 mg to treat the first qualifying prodrome event and placebo to treat the second qualifying prodrome event. An automated interactive web-response system used permuted blocks of four to manage randomisation. All people giving interventions and assessing outcomes were masked to group assignment during the study. People doing data analysis, which occurred after study completion, were not masked to group assignment. During the double-blind treatment period, each participant was instructed to orally take two tablets of the study drug at the onset of each qualifying prodrome event. The primary endpoint was absence of moderate or severe intensity headache within 24 h after study-drug dose; efficacy analyses were conducted with the modified intention-to-treat (mITT) population, defined as all randomly assigned participants with at least one headache assessment within 24 h after taking the study drug during the treatment period. The safety population included all treated participants who took at least one administration of study drug. The trial is registered with ClinicalTrials.gov (NCT04492020).

FINDINGS

Between Aug 21, 2020, and April 19, 2022, 518 participants were randomly assigned to double-blind crossover treatment. The safety population included 480 participants and the mITT population included 477 participants; 421 (88%) of 480 participants were female and 59 (12%) were male. Absence of moderate or severe headache within 24 h after a dose occurred after 190 (46%) of 418 qualifying prodrome events that had been treated with ubrogepant and after 121 (29%) of 423 qualifying prodrome events that had been treated with placebo (odds ratio 2·09, 95% CI 1·63-2·69; p<0·0001). Adverse events that occurred within 48 h after study-drug administration were reported after 77 (17%) of 456 qualifying prodrome events that had been treated with ubrogepant and after 55 (12%) of 462 events that had been treated with placebo.

INTERPRETATION

Ubrogepant was effective and well tolerated for the treatment of migraine attacks when taken during the prodrome.

FUNDING

AbbVie.

Pre- and post-headache phases of migraine: multi-country results from the CaMEO - International Study

BACKGROUND

Individuals with migraine frequently experience pre- and post-headache symptoms. This analysis aimed to characterize the relative frequency and burden of pre- and post-headache symptoms in people with migraine using data collected through the Chronic Migraine Epidemiology and Outcomes - International Study.

METHODS

This cross-sectional, observational, web-based survey was conducted in 2021-2022 in Canada, France, Germany, Japan, the United Kingdom, and the United States. Respondents who met modified International Classification of Headache Disorders, 3rd edition, criteria were offered the opportunity to participate. Information collected included migraine-related disability, depression/anxiety symptoms, cutaneous allodynia, activity limitations, and acute treatment optimization. Respondents indicated how often they had pre- or post-headache symptoms using a 5-point scale, ranging from 0 to 4, with a rating of 2 or higher classified as a pre- or post-headache symptom case. Modeling was used to examine relationships with monthly headache days (MHDs) and activity limitations during pre-headache and post-headache phases.

RESULTS

Among a total of 14,492 respondents, pre-headache symptoms were reported by 66.9%, while post-headache symptoms were reported by 60.2%. Both pre-headache and post-headache symptoms were reported by 49.5% of respondents, only pre-headache by 17.4%, only post-headache by 10.7%, and neither pre- nor post-headache symptoms by 22.4%. Compared with respondents who experienced only pre- or post-headache symptoms, respondents who experienced both pre- and post-headache symptoms had the highest rates of 4-7, 8-14, and ≥ 15 monthly headache days (23.1%, 14.1%, and 10.9%, respectively). Of respondents with both pre- and post-headache symptoms, 58.5% reported moderate-to-severe disability, 47.7% reported clinically significant symptoms of depression, 49.0% reported clinically significant symptoms of anxiety, and 63.8% reported cutaneous allodynia with headache (ASC-12). Moderate-to-severe activity limitations were reported during the pre-headache (29.5%) and post-headache phases (27.2%). For all outcomes modeled, after controlling for covariates, having pre-headache symptoms, post-headache symptoms, or both were associated with worse outcomes than having neither.

CONCLUSIONS

Pre- and post-headache phases of migraine are common, carry unrecognized burden, and may be a target for treatment.

Epidemiology, burden and clinical spectrum of cluster headache: a global update

BACKGROUND

This narrative review aims to broaden our understanding of the epidemiology, burden and clinical spectrum of cluster headache based on updated findings with a global perspective.

METHODS

We conducted a literature search on the following topics: (a) epidemiology; (b) burden: quality of life, disability, economic burden, job-related burden and suicidality; and (c) clinical spectrum: male predominance and its changes, age, pre-cluster and pre-attack symptoms, aura, post-drome, attack characteristics (location, severity, duration and associated symptoms), bout characteristics (attack frequency, bout duration and bout frequency), circadian and seasonal rhythmicity and disease course.

RESULTS

New large-scale population-based reports have suggested a lower prevalence than previous estimations. The impact of cluster headache creates a significant burden in terms of the quality of life, disability, economic and job-related burdens and suicidality. Several studies have reported decreasing male-to-female ratios and a wide age range at disease onset. The non-headache phases of cluster headache, including pre-cluster, pre-attack and postictal symptoms, have recently been revisited. The latest data regarding attack characteristics, bout characteristics, and circadian and seasonal rhythmicity from different countries have shown variability among bouts, attacks, individuals and ethnicities. Studies on the disease course of cluster headache have shown typical characteristics of attacks or bouts that decrease with time.

CONCLUSIONS

Cluster headache may be more than a "trigeminal autonomic headache" because it involves complex central nervous system phenomena. The spectrum of attacks and bouts is wider than previously recognised. Cluster headache is a dynamic disorder that evolves or regresses over time.

Migraine patients with and without neck pain: Differences in clinical characteristics, sensitization, musculoskeletal impairments, and psychological burden

AIMS

This study aims to assess differences in clinical characteristics across healthy controls and migraine patients with (MNP) and without (MwoNP) neck pain.

METHOD

This study assessed: headache frequency; headache disability index (HDI); central sensitization inventory (CSI); Hospital Anxiety (HADS-A) and Depression (HADS-D) scale; active range of motion (AROM); flexion rotation test (FRT); activation pressure score (APS); number of active/latent myofascial trigger points (MTrPs) in head/neck muscles; number of positive cervical vertebral segments (C1/C2) who reproduce migraine pain; wind-up ratio (WUR); mechanical pain threshold (MPT) and static pressure pain threshold (sPPT) over the trigeminal area; sPPT and dynamic PPT (dPPT) over the cervical area; sPPTs and MPT over the hand.

RESULTS

Compared to controls, MNP had: worse CSI, HADS-A, and HADS-D (all, p < 0.002); reduced AROM (flexion, extension, left lateral-flexion, and right-rotation), FRT, APS, and a higher number of MTrPs and positive cervical vertebral segments (all, p < 0.020); reduced trigeminal MPT and sPPT, cervical sPPT and dPPT, hand MPT and sPPT (all, p < 0.006). Compared to controls, MwoNP had: worse CSI, and HADS-A (all, p < 0.002); reduced AROM (flexion, and left lateral-flexion), FRT, APS, and a higher number of MTrPs and positive cervical vertebral segments (all, p < 0.017); reduced trigeminal MPT and cervical dPPT (all, p < 0.007). Compared to MwoNP, MNP had higher headache frequency, worse HDI and CSI (all, p < 0.006); reduced AROM (flexion, and right rotation) (all, p < 0.037); reduced cervical dPPT (all, p < 0.002).

CONCLUSION

MNP had worse headache characteristics, more pronounced cervical musculoskeletal impairments, enhanced signs and symptoms related to sensitization, and worse psychological burden compared to MwoNP.

Sex Differences in Clinical Features, Treatment, and Lifestyle Factors in Patients With Cluster Headache

BACKGROUND AND OBJECTIVES

Cluster headache is considered a male-dominated disorder, but we have previously suggested that female patients may display a more severe phenotype. Studies on sex differences in cluster headache have been conflicting; therefore, this study, with the largest validated cluster headache material at present, gives more insights into sex-specific characteristics of the disease. The objective of this study was to describe sex differences in patient demographics, clinical phenotype, chronobiology, triggers, treatment, and lifestyle in a Swedish cluster headache population.

METHODS

Study participants were identified by screening medical records from 2014 to 2020, requested from hospitals and neurology clinics in Sweden for the ICD-10 code G44.0 for cluster headache. Each study participant answered a detailed questionnaire on clinical information and lifestyle, and all variables were compared with regard to sex.

RESULTS

A total of 874 study participants with a verified cluster headache diagnosis were included. Of the participants, 575 (66%) were male and 299 (34%) were female, and biological sex matched self-reported sex for all. Female participants were to a greater extent diagnosed with the chronic cluster headache subtype compared with male participants (18% vs 9%, p = 0.0002). In line with this observation, female participants report longer bouts than male participants (p = 0.003) and used prophylactic treatment more often (60% vs 48%, p = 0.0005). Regarding associated symptoms, female participants experienced ptosis (61% vs 47%, p = 0.0002) and restlessness (54% vs 46%, p = 0.02) more frequently compared with male participants. More female than male study participants had a positive family history of cluster headache (15% vs 7%, p = 0.0002). In addition, female participants reported diurnal rhythmicity of their attacks more often than male participants (74% vs 63%, p = 0.002). Alcohol as a trigger occurred more frequently in male participants (54% vs 48%, p = 0.01), whereas lack of sleep triggering an attack was more common in female participants (31% vs 20%, p = 0.001).

DISCUSSION

With this in-depth analysis of a well-characterized cluster headache population, we could demonstrate that there are significant differences between male and female participants with cluster headache, which should be regarded at the time of diagnosis and when choosing treatment options. The data suggest that female patients generally may be more gravely affected by cluster headache than male patients.

FGF-21 and GDF-15 are increased in migraine and associated with the severity of migraine-related disability

BACKGROUND

Migraine is a prevalent disorder with significant socioeconomic impact. The impairment of metabolic homeostasis in migraine warrants further investigation. Changes in serum levels of Fibroblast-growth-factor 21 (FGF-21) and Growth-differentiation-factor 15 (GDF-15) are characteristic of some metabolic and mitochondrial diseases. This study aimed to assess whether the presence of migraine affects serum levels of FGF-21 and GDF-15, and taking metabolic disorders into account as potential confounding factors.

METHODS

We collected serum samples from 221 migraine patients (153 episodic migraineurs and 68 chronic migraineurs) and 124 healthy controls. The serum concentrations of FGF-21 and GDF-15 were measured using an enzyme-linked immunosorbent assay (ELISA) based approach. Clinical variables, including monthly headache days, peak headache pain intensity, the 6-item Headache Impact Test (HIT-6), and the Migraine Disability Assessment (MIDAS), were also addressed. The associations between the clinical variables of migraine patients and serum levels of FGF-21 and GDF-15 were studied.

RESULTS

In the multiple regression that corrected for age, we found that the serum levels of FGF-21 and GDF-15 were significantly higher in migraine sufferers than in healthy controls. A significant elevation in serum concentration of FGF-21, but not GDF-15, was observed in patients with chronic migraine (CM) compared to those with episodic migraine (EM). Regarding migraine-related disability, higher scores on the HIT-6 and MIDAS were associated with higher levels of FGF-21 and GDF-15. For the receiver operating characteristic (ROC) analysis, the diagnosis of migraine using GDF-15 showed that the area under the ROC curve (AUC) was 0.801 and the AUC of chronic migraine was 0.880.

CONCLUSION

Serum GDF-15 and FGF-21 levels are increased in patients with migraine and associated with the severity of migraine-related disability.

Galcanezumab effects on incidence of headache after occurrence of triggers, premonitory symptoms, and aura in responders, non-responders, super-responders, and super non-responders

BACKGROUND

The goal of this observational, open-label, cohort study was to determine whether prophylactic migraine treatment with galcanezumab, a peripherally acting drug, alters the incidence of premonitory symptoms, and/or occurrence of headache after exposure to triggers or aura episodes in treatment-responders (≥ 50% reduction in monthly migraine days [MMD]), super-responders (≥ 70%), non-responders (< 50%) and super non-responders (< 30%).

METHODS

Participants were administered electronic daily headache diaries to document migraine days and associated symptoms one month before and during the three months of treatment. Questionnaires were used to identify conscious prodromal and trigger events that were followed by headache prior to vs. after 3 months of treatment.

RESULTS

After 3 months of galcanezumab treatment, (a) the incidence of premonitory symptoms that were followed by headache decreased by 48% in the 27 responders vs. 28% in the 19 non-responders, and by 50% in the 11 super-responders vs. 12% in the 8 super non-responders; (b) the incidence of visual and sensory aura that were followed by headache was reduced in responders, non-responders, and super-responders, but not in super non-responders; (c) the number of triggers followed by headache decreased by 38% in responders vs. 13% in non-responders, and by 31% in super-responders vs. 4% in super non-responders; and (d) some premonitory symptoms (e.g., cognitive impairment, irritability, fatigue) and triggers (e.g., stress, sleeping too little, bright light, aura) were followed by headache only in super non-responders.

CONCLUSIONS

Mechanistically, these findings suggest that even a mild decrease in migraine frequency is sufficient to partially reverse the excitability and responsivity of neurons involved in the generation of certain triggers and potentially premonitory symptoms of migraine.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04271202. Registration date: February 10, 2020.

Migraine without aura

Migraine without aura is the commonest form of migraine in both children and adults. The diagnosis is made by applying the International Classification of Headache Disorders Third Edition subsection for migraine without aura (ICHD-3 subsection 1.1). Attacks in patients with migraine without aura are characterized by their polyphasic presentation (prodrome, headache phase, postdromal phase). The symptomatology of attacks is diverse and heterogeneous, with most common symptoms being photophobia, phonophobia, nausea, vomiting, and aggravation of pain by movement. The clinician and researcher who wants to learn about migraine without aura needs to be able to apply the ICHD-3 criteria with its specific symptomatology to make a correct diagnosis, but also needs to be aware about the plethora of symptoms patients may experience. In this chapter, the reader will explore the clinical phenotypical features of migraine without aura.

Migraine prodromes and migraine triggers

Migraine is characterized by a well-defined premonitory phase occurring hours or even days before the headache. Also, many migraineurs report typical triggers for their headaches. Triggers, however, are not consistent in their ability to precipitate migraine headaches. When looking at the clinical characteristics of both premonitory symptoms and triggers, a shared pathophysiological basis seems evident. Both seem to have their origin in basic homeostatic networks such as the feeding/fasting, the sleeping/waking, and the stress response network, all of which strongly rely on the hypothalamus as a hub of integration and are densely interconnected. They also influence the trigeminal pain processing system. Additionally, thalamic and hormonal mechanisms are involved. Activity within all those networks is influenced by various endogenous and external factors and might even cyclically change dependent on physiological internal rhythms. This might affect the threshold for the generation of migraine headaches. Premonitory symptoms thus appear as the result of an already ongoing alteration within those networks, whereas triggers might in this special situation only be able to further stress the system over the threshold for attack generation as catalysts of a process already in motion.

The premonitory phase of migraine is due to hypothalamic dysfunction: revisiting the evidence

OBJECTIVE

To critically appraise the evidence for and against premonitory symptoms in migraine being due to hypothalamic dysfunction.

DISCUSSION

Some premonitory symptoms (e.g. fatigue, mood changes, yawning, and food craving) are associated with the physiologic effects of neurotransmitters such as orexins, neuropeptide Y, and dopamine; all of which are expressed in hypothalamic neurons. In rodents, electrophysiologic recordings have shown that these neurotransmitters modulate nociceptive transmission at the level of second-order neurons in the trigeminocervical complex (TCC). Additional insights have been gained from neuroimaging studies that report hypothalamic activation during the premonitory phase of migraine. However, the available evidence is limited by methodologic issues, inconsistent reporting, and a lack of adherence to ICHD definitions of premonitory symptoms (or prodromes) in human experimental studies.

CONCLUSIONS

The current trend to accept that premonitory symptoms are due to hypothalamic dysfunction might be premature. More rigorously designed studies are needed to ascertain whether the neurobiologic basis of premonitory symptoms is due to hypothalamic dysfunction or rather reflects modulatory input to the trigeminovascular system from several cortical and subcortical areas. On a final note, the available epidemiologic data raises questions as to whether the existence of premonitory symptoms and even more so a distinct premonitory phase is a true migraine phenomenon. Video recording of the debate held at the 1st International Conference on Advances in Migraine Sciences (ICAMS 2022, Copenhagen, Denmark) is available at: https://www.youtube.com/watch?v=d4Y2x0Hr4Q8 .

Premonitory symptoms in migraine: a systematic review and meta-analysis of observational studies reporting prevalence or relative frequency

Background

Observational studies on the prevalence of premonitory symptoms in people with migraine, preceding the headache pain (or aura) phase, have shown conflicting results. We conducted a systematic review and meta-analysis to estimate the prevalence, and relative frequency among clinic populations, of premonitory symptoms in people with migraine, overall and of the multifarious individual symptoms, and to review the methodologies used to assess them.

Methods

We searched PubMed and Embase for studies published from database inception until 31st of May 2022. Two investigators independently screened titles, abstracts, and full texts. We retrieved observational studies that reported the prevalence/relative frequency of one or more premonitory symptoms in people with migraine. Two investigators independently extracted data and assessed risk of bias. Results were pooled using random-effects meta-analysis. Our main outcomes were the percentage of people with migraine who experienced at least one premonitory symptom and the percentages who experienced different individual premonitory symptoms. To describe our outcomes, we used the terms prevalence for data from population-based samples and relative frequency for data from clinic-based samples. We also descriptively and critically assessed the methodologies used to assess these symptoms.

Results

The pooled estimated prevalence in population-based studies of at least one premonitory symptom was 29% (95% CI: 8–63; I2 99%) and the corresponding pooled estimated relative frequency in clinic-based studies was 66% (95% CI: 45–82; I2 99%). The data from clinic-based studies only supported meta-analysis of 11 of 96 individual symptoms, with relative frequency estimates ranging from 11 to 49%. Risk of bias was determined as high in 20 studies, moderate in seven, and low in two.

Conclusions

The substantial between-study heterogeneity demands cautious interpretation of our estimates. Studies showed wide methodological variations, and many lacked rigor. Overall, the evidence was insufficient to support reliable prevalence estimation or characterization of premonitory symptoms. More data are needed, of better quality, to confirm the existence of a distinctive premonitory phase of migraine, and its features. Methodological guidelines based on expert consensus are a prerequisite.

Exploring the neurobiology of the premonitory phase of migraine preclinically - a role for hypothalamic kappa opioid receptors?

Background

The migraine premonitory phase is characterized in part by increased thirst, urination and yawning. Imaging studies show that the hypothalamus is activated in the premonitory phase. Stress is a well know migraine initiation factor which was demonstrated to engage dynorphin/kappa opioid receptors (KOR) signaling in several brain regions, including the hypothalamus. This study proposes the exploration of the possible link between hypothalamic KOR and migraine premonitory symptoms in rodent models.

Methods

Rats were treated systemically with the KOR agonist U-69,593 followed by yawning and urination monitoring. Apomorphine, a dopamine D1/2 agonist, was used as a positive control for yawning behaviors. Urination and water consumption following systemic administration of U-69,593 was also assessed. To examine if KOR activation specifically in the hypothalamus can promote premonitory symptoms, AAV8-hSyn-DIO-hM4Di (Gi-DREADD)-mCherry viral vector was microinjected into the right arcuate nucleus (ARC) of female and male KOR^CRE or KOR^WT mice. Four weeks after the injection, clozapine N-oxide (CNO) was administered systemically followed by the assessment of urination, water consumption and tactile sensory response.

Results

Systemic administration of U-69,593 increased urination but did not produce yawning in rats. Systemic KOR agonist also increased urination in mice as well as water consumption. Cell specific Gi-DREADD activation (i.e., inhibition through Gi-coupled signaling) of KOR^CRE neurons in the ARC also increased water consumption and the total volume of urine in mice but did not affect tactile sensory responses.

Conclusion

Our studies in rodents identified the KOR in a hypothalamic region as a mechanism that promotes behaviors consistent with clinically-observed premonitory symptoms of migraine, including increased thirst and urination but not yawning. Importantly, these behaviors occurred in the absence of pain responses, consistent with the emergence of the premonitory phase before the headache phase. Early intervention for preventive treatment even before the headache phase may be achievable by targeting the hypothalamic KOR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01497-7.

A Comprehensive Review of Zavegepant as Abortive Treatment for Migraine

Migraine headache is a widespread and complex neurobiological disorder that is characterized by unilateral headaches that are often accompanied by photophobia and phonophobia. Migraine is one of the leading chief complaints in the emergency department with negative impacts on quality of life and activities of daily living. The high number of emergency presentations also results in a significant economic burden. Its risk factors include family history, genetics, sex, race, socioeconomics, the existence of comorbid conditions, and level of education. Triggers include stress, light, noise, menstruation, weather, changes in sleep pattern, hunger, dehydration, dietary factors, odors, and alcohol. The International Headache Society has defined criteria for the diagnosis of migraine with and without aura. The pathophysiology of migraine headaches is multifactorial so there are a variety of treatment approaches. The current treatment approach includes abortive medications and prophylactic medications. Abortive medications include the first-line treatment of triptans, followed by ergot alkaloids, and calcitonin gene-related peptide (CGRP) receptor antagonists along with supplemental caffeine and antiemetics. Trigeminal afferents from the trigeminal ganglion innervate most cranial tissues and many areas of the head and face. These trigeminal afferents express certain biomarkers such as calcitonin gene-related peptide (CGRP), substance P, neurokinin A, and pituitary adenylate cyclase-activating polypeptide that are important to the pain and sensory aspect of migraines. In this comprehensive review, we discuss Zavegepant, a calcitonin gene-related peptide receptor antagonist, as a new abortive medication for migraine headaches.

Migraine Pathophysiology in Children and Adolescents: A Review of the Literature

Although migraine in adult and pediatric patients are overall very similar to each other, differences in prevalence, presentation, and treatment efficacy may reflect slight differences in the pathophysiological processes underlying migraine in these patient groups, perhaps because of ongoing development of the nervous system during childhood and adolescence. Although major gains have been made in understanding the pathophysiology of migraine in adults in recent years, equivalent research on migraine in pediatric patients continues to lag behind. In this review, we will describe the current state of migraine research in pediatric patients with regard to presentation and frequency of prodromal and postdromal symptoms, ictal and interictal calcitonin gene-related peptide elevation, and evidence for cortical spreading depression, thus covering all phases of migraine, and discuss how the findings seen here may relate to possible underlying pathophysiological mechanisms of migraine. We aim to elucidate possible differences between migraine in children and adults, and the need for further research specific to pediatric patients with migraine in order to improve treatment in this patient group.

Efficacy and safety of eptinezumab in patients with migraine and self-reported aura: Post hoc analysis of PROMISE-1 and PROMISE-2

Background

This post hoc subgroup analysis evaluated the efficacy and safety of eptinezumab for migraine prevention in patients with migraine and self-reported aura.

Methods

PROMISE-1 (NCT02559895; episodic migraine) and PROMISE-2 (NCT02974153; chronic migraine) were randomized, double-blind, placebo-controlled trials that evaluated eptinezumab for migraine prevention. In both studies, the primary outcome was the mean change from baseline in monthly migraine days over Weeks 1–12. Patients in this analysis included those who self-reported migraine with aura at screening.

Results

Of patients with episodic migraine, ∼75% reported a history of aura at screening; of patients with chronic migraine, ∼35% reported a history of aura. Changes in monthly migraine days over Weeks 1–12 were –4.0 (100 mg) and –4.2 (300 mg) with eptinezumab versus –3.1 with placebo in patients with episodic migraine with aura, and were –7.1 (100 mg) and –7.6 (300 mg) with eptinezumab versus –6.0 with placebo in patients with chronic migraine with aura. Treatment-emergent adverse events were reported by 56.0% (100 mg), 57.4% (300 mg), and 55.4% (placebo) of patients.

Conclusions

The preventive migraine efficacy of eptinezumab in patients in the PROMISE studies who self-reported aura was comparable to the overall study populations, demonstrating a similarly favorable safety and tolerability profile.

Trial registration: ClinicalTrials.gov Identifiers: NCT02559895 and NCT02974153

Migraine

Migraine is a common, chronic, disorder that is typically characterized by recurrent disabling attacks of headache and accompanying symptoms, including aura. The aetiology is multifactorial with rare monogenic variants. Depression, epilepsy, stroke and myocardial infarction are comorbid diseases. Spreading depolarization probably causes aura and possibly also triggers trigeminal sensory activation, the underlying mechanism for the headache. Despite earlier beliefs, vasodilation is only a secondary phenomenon and vasoconstriction is not essential for antimigraine efficacy. Management includes analgesics or NSAIDs for mild attacks, and, for moderate or severe attacks, triptans or 5HT_1B/1D receptor agonists. Because of cardiovascular safety concerns, unreliable efficacy and tolerability issues, use of ergots to abort attacks has nearly vanished in most countries. CGRP receptor antagonists (gepants) and lasmiditan, a selective 5HT1_F receptor agonist, have emerged as effective acute treatments. Intramuscular onabotulinumtoxinA may be helpful in chronic migraine (migraine on ≥15 days per month) and monoclonal antibodies targeting CGRP or its receptor, as well as two gepants, have proven effective and well tolerated for the preventive treatment of migraine. Several neuromodulation modalities have been approved for acute and/or preventive migraine treatment. The emergence of new treatment targets and therapies illustrates the bright future for migraine management.

The Bárány Society position on 'Cervical Dizziness'

This paper describes the Bárány Society Classification OverSight Committee (COSC) position on Cervical Dizziness, sometimes referred to as Cervical Vertigo. This involved an initial review by a group of experts across a broad range of fields, and then subsequent review by the Bárány Society COSC. Based upon the so far published literature, the Bárány Society COSC takes the view that the evidence supporting a mechanistic link between an illusory sensation of self-motion (i.e. vertigo - spinning or otherwise) and neck pathology and/or symptoms of neck pain - either by affecting the cervical vertebrae, soft tissue structures or cervical nerve roots - is lacking. When a combined head and neck movement triggers an illusory sensation of spinning, there is either an underlying common vestibular condition such as migraine or BPPV or less commonly a central vestibular condition including, when acute in onset, dangerous conditions (e.g. a dissection of the vertebral artery with posterior circulation stroke and, exceedingly rarely, a vertebral artery compression syndrome). The Committee notes, that migraine, including vestibular migraine, is by far, the commonest cause for the combination of neck pain and vestibular symptoms. The committee also notes that since head movement aggravates symptoms in almost any vestibular condition, the common finding of increased neck muscle tension in vestibular patients, may be linked as both cause and effect, to reduced head movements. Additionally, there are theoretical mechanisms, which have not been explored, whereby cervical pain may promote vaso-vagal, cardio-inhibitory reflexes and hence by presyncopal mechanisms, elicit   transient   disorientation and/or imbalance. The committee accepts that further research is required to answer the question as to whether those rare cases in which neck muscle spasm is associated with a vague sense of spatial disorientation and/or imbalance, is indeed linked to impaired neck proprioception. Future studies should ideally be placebo controlled and double-blinded where possible, with strict inclusion and exclusion criteria that aim for high specificity at the cost of sensitivity. To facilitate further studies in "cervical dizziness/vertigo", we provide a narrative view of the important confounds investigators should consider when designing controlled mechanistic and therapeutic studies. Hence, currently, the Bárány COSC refrains from proposing any preliminary diagnostic criteria for clinical use outside a research study. This position may change as new research evidence is provided.

Was it something I ate? Understanding the bidirectional interaction of migraine and appetite neural circuits

Migraine attacks can involve changes of appetite: while fasting or skipping meals are often reported triggers in susceptible individuals, hunger or food craving are reported in the premonitory phase. Over the last decade, there has been a growing interest and recognition of the importance of studying these overlapping fields of neuroscience, which has led to novel findings. The data suggest additional studies are needed to unravel key neurobiological mechanisms underlying the bidirectional interaction between migraine and appetite. Herein, we review information about the metabolic migraine phenotype and explore migraine therapeutic targets that have a strong input on appetite neuronal circuits, including the calcitonin gene-related peptide (CGRP), the pituitary adenylate cyclase-activating polypeptide (PACAP) and the orexins. Furthermore, we focus on potential therapeutic peptide targets that are involved in regulation of feeding and play a role in migraine pathophysiology, such as neuropeptide Y, insulin, glucagon and leptin. We then examine the orexigenic - anorexigenic circuit feedback loop and explore glucose metabolism disturbances. Additionally, it is proposed a different perspective on the most reported feeding-related trigger - skipping meals - as well as a link between contrasting feeding behaviors (skipping meals vs food craving). Our review aims to increase awareness of migraine through the lens of appetite neurobiology in order to improve our understanding of the earlier phase of migraine, encourage better studies and cross-disciplinary collaborations, and provide novel migraine-specific therapeutic opportunities.

CGRP and CGRP-receptor as targets of migraine therapy: Brain Prize-2021

BACKGROUND

Migraine is a highly prevalent primary headache with an unclear pathomechanism. During the last 40 years numerous hypotheses have arisen, among them the theory of the trigeminovascular system is the primary one. It serves as a skeleton in successful preclinical studies and in the development of effective therapeutic options for migraine headache.

OBJECTIVE

The Brain Prize (awarded annually by the Lundbeck Foundation) is the most prestigious tribute in neuroscience. The winners in 2021 were Lars Edvinsson, Peter Goadsby, Michael Moskowitz and Jes Olesen. They are the fathers of the migraine pathomechanism which led to revolutionary new treatments. This review summarizes their landmark findings.

METHODS

Data related to this topic were reviewed from PubMed records published between 1979 and May 2021. Searches were based on preclinical and clinical studies in the covered field. The findings were listed in chronological order. From a therapeutic perspective, only randomized controlled trials and meta-analysis were discussed.

RESULTS

The calcitonin gene-related peptide-related pathogenesis of migraine is based on the activation of the trigeminovascular system. The therapeutic triad for migraine is triptans, gepants and calcitonin gene-related peptide-targeted monoclonal antibodies.

CONCLUSION

In the past 40 years, the systematic work of leading headache scientists has resulted in robust theoretical and therapeutic knowledge in the preclinical and clinical study of migraine.

The Enduring Controversy of Cervicogenic Vertigo, and Its Place among Positional Vertigo Syndromes

The idea of cervicogenic vertigo (CV) was proposed nearly a century ago, yet despite considerable scrutiny and research, little progress has been made in clarifying the underlying mechanism of the disease, developing a confirmatory diagnostic test, or devising an appropriately targeted treatment. Given the history of this idea, we offer a review geared towards understanding why so many attempts at clarifying it have failed, with specific comments regarding how CV fits into the broader landscape of positional vertigo syndromes, what a successful diagnostic test might require, and some practical advice on how to approach this in the absence of a diagnostic test.

Migraine: beyond pain

Most people who see, treat or experience migraine will be aware that its clinical manifestations exceed the symptom of head pain. However, available acute treatments so far have targeted migraine symptoms only in the context of the pain phase of an attack. The associated disability clearly involves more than just these symptoms, and the phenotype can include additional painless features, including alterations in mood, cognition and homeostasis and sensory sensitivities. Recognising these symptoms, understanding their neurobiological basis and systematically recording them prospectively in clinical therapeutic trials are likely to offer valuable pathophysiological and therapeutic insights into this complex brain disorder, ultimately helping to improve the quality of lives of sufferers. We aim to explore the multifaceted disorder that is migraine, with a particular focus on the non-painful non-aura symptoms.

Hypothalamic functional MRI activity in the initiation phase of spontaneous and glyceryl trinitrate-induced migraine attacks

The hypothalamus has been suggested to be important in the initiation cascade of migraine attacks based on clinical and biochemical observations. Previous imaging studies could not disentangle the changes due to the attack and those due to the trigger compound. With a novel approach, we assessed hypothalamic neuronal activity in early premonitory phases of glyceryl‐trinitrate (GTN)‐induced and spontaneous migraine attacks. We measured the hypothalamic blood oxygen level‐dependent (BOLD) response to oral glucose ingestion with 3T‐functional magnetic resonance imaging (MRI) in 27 women, 16 with migraine without aura and 11 controls group matched for age and body mass index (BMI), on 1 day without prior GTN administration and on a second day after GTN administration (to coincide with the premonitory phase of an induced attack). Interestingly, subgroups of patients with and without GTN‐triggered attacks could be compared. Additionally, five migraineurs were investigated in a spontaneous premonitory phase. Linear mixed models were used to study between‐ and within‐group effects. Without prior GTN infusion, the BOLD response to glucose was similar in migraine participants and controls (P = .41). After prior GTN infusion, recovery occurred steeper and faster in migraineurs (versus Day 1; P < .0001) and in those who developed an attack versus those who did not (P < .0001). Prior GTN infusion did not alter the glucose‐induced response in controls (versus baseline; P = .71). Just before spontaneous attacks, the BOLD‐response recovery was also faster (P < .0001). In this study, we found new and direct evidence of altered hypothalamic neuronal function in the immediate preclinical phase of both GTN‐provoked and spontaneous migraine attacks.

Migraine Is More Than Just Headache: Is the Link to Chronic Fatigue and Mood Disorders Simply Due to Shared Biological Systems?

Migraine is a symptomatically heterogeneous condition, of which headache is just one manifestation. Migraine is a disorder of altered sensory thresholding, with hypersensitivity among sufferers to sensory input. Advances in functional neuroimaging have highlighted that several brain areas are involved even prior to pain onset. Clinically, patients can experience symptoms hours to days prior to migraine pain, which can warn of impending headache. These symptoms can include mood and cognitive change, fatigue, and neck discomfort. Some epidemiological studies have suggested that migraine is associated in a bidirectional fashion with other disorders, such as mood disorders and chronic fatigue, as well as with other pain conditions such as fibromyalgia. This review will focus on the literature surrounding alterations in fatigue, mood, and cognition in particular, in association with migraine, and the suggested links to disorders such as chronic fatigue syndrome and depression. We hypothesize that migraine should be considered a neural disorder of brain function, in which alterations in aminergic networks integrating the limbic system with the sensory and homeostatic systems occur early and persist after headache resolution and perhaps interictally. The associations with some of these other disorders may allude to the inherent sensory sensitivity of the migraine brain and shared neurobiology and neurotransmitter systems rather than true co-morbidity.

Pathophysiology of Migraine

PURPOSE OF REVIEW

This article summarizes the current understanding of the pathophysiology of migraine, including some controversial aspects of the underlying mechanisms of the disorder.

RECENT FINDINGS

Recent functional neuroimaging studies focusing on the nonpainful symptoms of migraine have identified key areas of the central nervous system implicated in the early phases of a migraine attack. Clinical studies of spontaneous and provoked migraine attacks, together with preclinical studies using translational animal models, have led to a better understanding of the disease and the development of disease-specific and targeted therapies.

SUMMARY

Our knowledge of the pathophysiology of migraine has advanced significantly in the past decades. Current evidence supports our understanding of migraine as a complex cyclical brain disorder that likely results from dysfunctional sensory processing and dysregulation of homeostatic mechanisms. This article reviews the underlying mechanisms of the clinical manifestations of each phase of the migraine cycle.

Premonitory symptoms in glyceryl trinitrate triggered migraine attacks: a case-control study

ABSTRACT

Spontaneous and pharmacologically provoked migraine attacks are frequently preceded by nonheadache symptoms called premonitory symptoms. Here, we systematically evaluated premonitory symptoms in migraine patients and healthy controls after glyceryl trinitrate (GTN) infusion. In women with migraine without aura (n = 34) and age-matched female controls (n = 24), we conducted systematically a semistructured interview assessing 21 possible premonitory symptoms every 15 minutes in the 5 hours after GTN infusion (0.5 µg/kg/min over 20 minutes). Migraine-like headaches occurred in 28/34 (82.4%) migraineurs (GTN responders). After GTN, 26/28 (92.9%) responders, 6/6 (100%) nonresponders, and 13/24 (54.2%) controls reported at least one possible premonitory symptom. Concentration difficulties (P = 0.011), yawning (P = 0.009), nausea (P = 0.028), and photophobia (P = 0.001) were more frequently reported by those migraineurs who developed a migraine-like attack vs healthy controls. Importantly, concentration difficulties were exclusively reported by those who developed a migraine-like attack. Thus, our findings support the view that GTN is able to provoke the naturally occurring premonitory symptoms and show that yawning, nausea, photophobia, and concentration difficulties are most specific for an impending GTN-induced migraine-like headache. We suggest that these symptoms may also be helpful as early warning signals in clinical practice with concentration difficulties exclusively reported by those who develop a migraine-like attack.

Are some patient-perceived migraine triggers simply early manifestations of the attack?

OBJECTIVE

To study the agreement between self-reported trigger factors and early premonitory symptoms amongst a group of migraineurs in both spontaneous and pharmacologically provoked attacks.

METHODS

Fifty-three subjects with migraine with and without aura, with ≤ 22 headache days/month, with spontaneous premonitory symptoms associated with migraine attacks were recruited nationally. A detailed history was taken by a study investigator to confirm diagnosis and extended phenotyping was performed to identify patient-reported triggers for migraine attacks, premonitory symptom phenotype and headache characteristics, using a standardised physician-administered questionnaire. The same subjects were exposed to a 0.5 mcg/kg/min nitroglycerin infusion over 20 min, to determine if similar migraine symptoms could be triggered. The triggered attacks were phenotyped in the same way as spontaneous ones. Percentage agreement and Cohen's kappa measure of agreement were used to identify concordance between patient-reported triggers and the corresponding spontaneous and triggered premonitory symptoms. Percentage agreement of > 60% and/or a kappa value > 0.3 with P < 0.05 were considered significant.

RESULTS

There was statistically significant agreement between perception of light as a migraine trigger and spontaneous premonitory photophobia; perception of sound as a trigger and triggered premonitory phonophobia; skipping meals as a trigger and spontaneous premonitory food cravings; and food triggers and spontaneous premonitory food cravings. There was good agreement between stress and premonitory triggered mood change.

CONCLUSIONS

At least some patient-reported triggers, such as light, sound, foods and skipping meals, may represent early brain manifestations of the premonitory phase of the migraine attack.

Premonitory symptoms in migraine from China: A multi-clinic study of 4821 patients

OBJECTIVE

To observe the prevalence and characteristics of premonitory symptoms in Chinese migraineurs and explore their associations with migraine-related factors.

METHOD

Migraineurs who visited a tertiary headache clinic and one of nine neurology clinics between May 2014 and November 2019 were studied.

RESULT

Among the 4821 patients meeting the migraine criteria (International Classification of Headache Disorders, 3rd edition), 1038 (21.5%) patients experienced at least one premonitory symptom. The most common premonitory symptoms were neck stiffness, dizziness, yawning and drowsiness. The logistic regression analysis demonstrated that aura, photophobia, aggravation by routine physical activity, triggers, family history, depression, coffee consumption and physical exercise were associated with an increased probability of experiencing premonitory symptoms (p ≤ 0.001). The premonitory symptoms of migraine with and without aura differ in prevalence and most common symptoms. The cluster analysis revealed pairwise clustering of the following premonitory symptoms: Photophobia/phonophobia, concentration change/dysesthesia, loquacity/overactivity, yawning/drowsiness, fatigue/dizziness, and mood change/irritability. The correlation analysis of triggers and premonitory symptoms revealed that temperature change, environment change, sleep disorder, activity and stress were related to multiple premonitory symptoms, and that food, light, menstruation, alcohol and odor were related to special premonitory symptoms (p ≤ 0.001).

CONCLUSION

The prevalence of premonitory symptoms among migraineurs in China is 21.5%. Some factors influence the probability of experiencing premonitory symptoms. Paired premonitory symptoms in the clustering analysis may share similar origins. Certain triggers associated with multiple premonitory symptoms may induce brain dysfunction; however, other triggers that overlap with corresponding special premonitory symptoms may be premonitory symptoms or a form of premonitory symptom.

New Instrument for the Evaluation of Prodromes and Attacks of Hereditary Angioedema (HAE-EPA)

A disease-specific, patient-reported outcome instrument suitable for evaluation of prodromes and attacks of hereditary angioedema (HAE) is a clinical unmet need. We constructed such instrument and examined its validity, acceptability, and discriminative ability. Sixty-six patients participated in a survey addressing their demographics, social, and medical status. Discriminant content validity involved: (1) construct definition by in-depth cognitive debriefing interviews, (2) item selection identifying relevant categories, and (3) judgment of the format whereby questionnaires were tested on experienced patients and its content/reliability was validated. Prodromes and attacks affecting certain body systems (domains) were organized in "clusters". Internal consistency, content, and convergent validities were analyzed. Analyses of variance and regression models were used to evaluate the discriminative ability of the instrument to differentiate between attacks and prodromes. The study demonstrates very high internal consistency (Cronbach's α: attacks 0.88-0.98, prodromes 0.78-0.98). Analysis of variance confirmed significant differences between all dimensions and in pre-defined clusters (F (4, 61) = 45.74, p < 0.001, Eta² = 0.77). Significant correlations were found between dimensions of prodromes and attacks. Prodromes are associated but differentiated from attacks. Correlations in severity were high for all domains. Interactions were found between prodromes and patients' experience in illness. In conclusion, the new Prodrome-Attack Evaluation questionnaire (HAE-EPA) is capable of distinguishing attacks and prodromes of HAE, as well as determining associations between the two interrelated phenomena. The new instrument achieves the required discriminative ability, acceptability, and content validity/reliability and therefore can be used as a reliable tool for the investigation of prodromes, attacks, and their relationships.

The Enigma of Prodromes in Hereditary Angioedema (HAE)

A prodrome is a premonitory set of signs and symptoms indicating the onset of a disease. Prodromes are frequently reported by hereditary angioedema (HAE) patients, antedating attacks by a few hours or even longer. In some studies, high incidence of prodromes was reported by patients, with considerable number being able to predict oncoming attacks. Regrettably, prodromes have never received a consensual definition and have not been properly investigated in a systematic fashion. Therefore, their nature remains elusive and their contribution to the diagnosis and treatment of disorders is uncertain. The term "prodrome," as used in various pathologies, denotes different meanings, timing, and duration, so it may not be equally suitable for all clinical situations. Perception of a prodrome is unique for each individual patient depending on self-experience. As modern drugs delegate the administration decision to the patients, early detection of a developing attack may help mitigate its severity and allow deployment of appropriate therapy. New diagnostic instruments were recently developed that can assist in defining the attributes of prodromes and their association with attacks. We will review the prodrome phenomenon as exhibited in certain clinical situations, with an emphasis on prodromes of HAE.

Sex differences in prevalence of migraine trigger factors: A cross-sectional study

AIM

To examine the effect of sex on migraine trigger factors.

METHODS

Prevalence of 11 frequently reported trigger factors was determined in a cross-sectional study among migraine patients from a validated migraine database (n = 5725 females and n = 1061 males). Female-to-male odds ratios were calculated for each trigger, using a logistic regression model with attack frequency and migraine subtype (with or without aura) as covariates. Additionally, the effect of sex on total number of triggers per individual was determined.

RESULTS

The top three most reported triggers in women were menstruation (78%), stress (77%), and bright light (69%). Men reported stress (69%), bright light (63%), and sleep deprivation (60%) most frequently as provoking factors. The following triggers were more often reported by women than men: Bright light (odds ratio 1.29 [95% CI 1.12-1.48]; p = 0.003), stress (1.47 [1.27-1.69]; p < 0.001), skipping a meal (1.24 [1.09-1.42]; p = 0.015), sleep deprivation (1.37 [1.20-1.57]; p < 0.001), high altitudes (1.70 [1.40-2.09]; p < 0.001), and weather changes (1.35 [1.18-1.55]; p < 0.001). Women reported more triggers than men, even when menstruation was disregarded (mean ± SD: 4.6 ± 2.3 and 4.3 ± 2.3; p < 0.001).Conclusion: Women report migraine trigger factors to be provocative of their attacks more frequently than men, which may be related to a lower migraine threshold due to sex hormonal changes.

Development and Internal Validation of a Multivariable Prediction Model for Individual Episodic Migraine Attacks Based on Daily Trigger Exposures

OBJECTIVE

To develop and internally validate a multivariable predictive model for days with new-onset migraine headaches based on patient self-prediction and exposure to common trigger factors.

BACKGROUND

Accurate real-time forecasting of one's daily risk of migraine attack could help episodic migraine patients to target preventive medications for susceptible time periods and help decrease the burden of disease. Little is known about the predictive utility of common migraine trigger factors.

METHODS

We recruited adults with episodic migraine through online forums to participate in a 90-day prospective daily-diary cohort study conducted through a custom research application for iPhone. Every evening, participants answered questions about migraine occurrence and potential predictors including stress, sleep, caffeine and alcohol consumption, menstruation, and self-prediction. We developed and estimated multivariable multilevel logistic regression models for the risk of a new-onset migraine day vs a healthy day and internally validated the models using repeated cross-validation.

RESULTS

We had 178 participants complete the study and qualify for the primary analysis which included 1870 migraine events. We found that a decrease in caffeine consumption, higher self-predicted probability of headache, a higher level of stress, and times within 2 days of the onset of menstruation were positively associated with next-day migraine risk. The multivariable model predicted migraine risk only slightly better than chance (within-person C-statistic: 0.56, 95% CI: 0.54, 0.58).

CONCLUSIONS

In this study, episodic migraine attacks were not predictable based on self-prediction or on self-reported exposure to common trigger factors. Improvements in accuracy and breadth of data collection are needed to build clinically useful migraine prediction models.

Sex and the serotonergic underpinnings of depression and migraine

Most psychiatric disorders demonstrate sex differences in their prevalence and symptomatology, and in their response to treatment. These differences are particularly pronounced in mood disorders. Differences in sex hormone levels are among the most overt distinctions between males and females and are thus an intuitive underpinning for these clinical observations. In fact, treatment with estrogen and testosterone was shown to exert antidepressant effects, which underscores this link. Changes to monoaminergic signaling in general, and serotonergic transmission in particular, are understood as central components of depressive pathophysiology. Thus, modulation of the serotonin system may serve as a mechanism via which sex hormones exert their clinical effects in mental health disorders. Over the past 20 years, various experimental approaches have been applied to identify modes of influence of sex and sex hormones on the serotonin system. This chapter provides an overview of different molecular components of the serotonin system, followed by a review of studies performed in animals and in humans with the purpose of elucidating sex hormone effects. Particular emphasis will be placed on studies performed with positron emission tomography, a method that allows for human in vivo molecular imaging and, therefore, assessment of effects in a clinically representative context. The studies addressed in this chapter provide a wealth of information on the interaction between sex, sex hormones, and serotonin in the brain. In general, they offer evidence for the concept that the influence of sex hormones on various components of the serotonin system may serve as an underpinning for the clinical effects these hormones demonstrate.

The migraineur’s brain networks: Continuous resting state fMRI over 30 days

Objective

The aim of the current study was to identify typical alterations in resting state connectivity within different stages of the migraine cycle and to thus explore task-free mechanisms of headache attack generation in migraineurs.

Background

Recent evidence in migraine pathophysiology suggests that hours and even days before headache certain changes in brain activity take place, ultimately leading to an attack. Here, we investigate changes before headache onset using resting state functional magnetic resonance imaging (fMRI).

Methods

Nine episodic migraineurs underwent daily resting state functional magnetic resonance imaging for a minimum period of 30 consecutive days, leading to a cumulative number of 282 total days scanned. Thus, data from 15 spontaneous headache attacks were acquired. This allows analysing not only the ictal and the interictal phase of migraine but also the preictal phase. ROI-to-ROI (region of interest) and ROI-to-voxel connectivity was calculated over the migraine cycle.

Results

Within the ROI-to-ROI analysis, the right nucleus accumbens showed enhanced functional connectivity to the left amygdala, hippocampus and gyrus parahippocampalis in the preictal phase compared to the interictal phase. ROI-to-voxel connectivity of the right accumbens with the dorsal rostral pons was enhanced during the preictal phase compared to interictally. Regarding custom defined ROIs, the dorsal pons was ictally functionally more strongly coupled to the hypothalamic area than interictally.

Conclusions

This unique data set suggests that particularly connectivity changes in dopaminergic centres and between the dorsal pons and the hypothalamus are important within migraine attack generation and sustainment.

Metabolomics markers in Neurology: current knowledge and future perspectives for therapeutic targeting

INTRODUCTION

Metabolomics is an emerging approach providing new insights into the metabolic changes and underlying mechanisms involved in the pathogenesis of neurological disorders.

AREAS COVERED

Here, the authors present an overview of the current knowledge of metabolic profiling (metabolomics) to provide critical insight on the role of biochemical markers and metabolic alterations in neurological diseases.

EXPERT OPINION

Elucidation of characteristic metabolic alterations in neurological disorders is crucial for a better understanding of their pathogenesis, and for identifying potential biomarkers and drug targets. Nevertheless, discrepancies in diagnostic criteria, sample handling protocols, and analytical methods still affect the generalizability of current study results.

An Evidence-Based Review of Fremanezumab for the Treatment of Migraine

Migraine headache is a common, chronic, debilitating disease with a complex etiology. Current therapy for migraine headache comprises either treatments targeting acute migraine pain or prophylactic therapy aimed at increasing the length of time between migraine episodes. Recent evidence suggests that calcium gene-related peptide (CGRP) is a critical component in the pathogenesis of migraines. Fremanezumab, a monoclonal antibody against CGRP, was recently approved by the Food and Drug Administration (FDA) after multiple studies showed that it was well-tolerated, safe, and effective in the treatment of migraines. Further research is needed to elucidate the long-term effects of fremanezumab and CGRP-antagonists in general, and additional data is required in less healthy patients to estimate its effects in these populations and potentially increase the eligible group of recipients. This is a comprehensive review of the current literature on the efficacy and safety of fremanezumab for the treatment of chronic migraine. In this review we provide an update on the epidemiology, pathogenesis, diagnosis, and current treatment of migraine, and summarize the evidence for fremanezumab as a treatment for migraine.

Tracking the Migraine Cycle Using Visual Tasks

There are a number of reports that perceptual, electrophysiological and imaging measures can track migraine periodicity. As the electrophysiological and imaging research requires specialist equipment, it has few practical applications. This study sought to track changes in performance on four visual tasks over the migraine cycle. Coherence thresholds were measured for two motion and two orientation tasks. The first part of the study confirmed that the data obtained from an online study produced comparable results to those obtained under controlled laboratory conditions. Thirteen migraine with aura, 12 without aura, and 12 healthy controls participated. The second part of the study showed that thresholds for discriminating vertical coherent motion varied with the migraine cycle for a majority of the participants who tested themselves multiple times (four with aura, seven without). Performance improved two days prior to a migraine attack and remained improved for two days afterwards. This outcome is as expected from an extrapolation of earlier electrophysiological research. This research points to the possibility of developing sensitive visual tests that patients can use at home to predict an impending migraine attack and so take steps to try to abort it or, if it is inevitable, to plan their lives around it.

Imaging the Premonitory Phase of Migraine

Migraine is a common and disabling brain disorder with a broad and heterogeneous phenotype, involving both pain and painless symptoms. Over recent years, more clinical and research attention has been focused toward the premonitory phase of the migraine attack, which can start up to days before the onset of head pain. This early phase can involve symptomatology, such as cognitive and mood change, yawning, thirst and urinary frequency and sensory sensitivities, such as photophobia and phonophobia. In some patients, these symptoms can warn of an impending headache and therefore offer novel neurobiological insights and therapeutic potential. As well as characterization of the phenotype of this phase, recent studies have attempted to image this early phase using functional neuroimaging and tried to understand how the symptoms are mediated, how a migraine attack may be initiated, and how nociception may follow thereafter. This review will summarize the recent and evolving findings in this field and hypothesize a mechanism of subcortical and diencephalic brain activation during the start of the attack, including that of basal ganglia, hypothalamus, and thalamus prior to headache, which causes a top-down effect on brainstem structures involved in trigeminovascular nociception, leading ultimately to headache.

Plasma Glucose Levels Increase During Spontaneous Attacks of Migraine With and Without Aura

OBJECTIVE

To investigate plasma glucose changes during the ictal state of migraine compared to the interictal state.

BACKGROUND

Previous studies suggest abnormal glucose metabolism in migraine patients during and outside of attacks. It is not known if plasma glucose levels change during spontaneous migraine attacks.

METHODS

Plasma glucose levels were measured during and outside of spontaneous migraine attacks with and without aura. Plasma glucose values were corrected for diurnal variation of plasma glucose by subtracting the difference between the moving average (intervals of 2 hours) and overall mean from the plasma glucose values.

RESULTS

This was a sub-study of a larger study conducted at Rigshospitalet Glostrup in the Capital Region of Denmark. Thirty-one patients (24 F, 7 M, 13 with aura, 18 without aura) were included in the study. Mean time from attack onset to blood sampling was 7.6 hours. Mean pain at the time of investigation was 6 on a 0-10 verbal rating scale. Plasma glucose was higher ictally compared to the interictal phase (interictal mean: 88.63 mg/dL, SD 11.70 mg/dL; ictal mean: 98.83 mg/dL, SD 13.16 mg/dL, difference 10.20 mg/dL, 95% CI = [4.30; 16.10]), P = .0014). The ictal increase was highest in patients investigated early during attacks and decreased linearly with time from onset of migraine (-1.57 mg/dL/hour from onset of attack, P = .020). The attack-related increase in blood glucose was not affected by pain intensity or presence of aura symptoms.

CONCLUSIONS

We demonstrated higher plasma glucose values during spontaneous migraine attacks, independent of the presence of aura symptoms and not related to pain intensity, peaking in the early phase of attacks. Additional studies are necessary to confirm our findings and explore the possible underlying mechanisms.

Caffeine and Primary (Migraine) Headaches-Friend or Foe?

Background: The actions of caffeine as an antagonist of adenosine receptors have been extensively studied, and there is no doubt that both daily and sporadic dietary consumption of caffeine has substantial biological effects on the nervous system. Caffeine influences headaches, the migraine syndrome in particular, but how is unclear. Materials and Methods: This is a narrative review based on selected articles from an extensive literature search. The aim of this study is to elucidate and discuss how caffeine may affect the migraine syndrome and discuss the potential pathophysiological pathways involved. Results: Whether caffeine has any significant analgesic and/or prophylactic effect in migraine remains elusive. Neither is it clear whether caffeine withdrawal is an important trigger for migraine. However, withdrawal after chronic exposure of caffeine may cause migraine-like headache and a syndrome similar to that experienced in the prodromal phase of migraine. Sensory hypersensitivity however, does not seem to be a part of the caffeine withdrawal syndrome. Whether it is among migraineurs is unknown. From a modern viewpoint, the traditional vascular explanation of the withdrawal headache is too simplistic and partly not conceivable. Peripheral mechanisms can hardly explain prodromal symptoms and non-headache withdrawal symptoms. Several lines of evidence point at the hypothalamus as a locus where pivotal actions take place. Conclusion: In general, chronic consumption of caffeine seems to increase the burden of migraine, but a protective effect as an acute treatment or in severely affected patients cannot be excluded. Future clinical trials should explore the relationship between caffeine withdrawal and migraine, and investigate the effects of long-term elimination.

Current understanding of premonitory networks in migraine: A window to attack generation

Aim

To describe neuronal networks underlying commonly reported migraine premonitory symptoms and to discuss how these might precipitate migraine pain.

Background

Migraine headache is frequently preceded by a distinct and well characterized premonitory phase including symptoms like yawning, sleep disturbances, alterations in appetite and food intake and hypersensitivity to certain external stimuli. Recent neuroimaging studies strongly suggest the hypothalamus as the key mediator of the premonitory phase and also suggested alterations in hypothalamic networks as a mechanism of migraine attack generation. When looking at the vast evidence from basic research within the last decades, hypothalamic and thalamic networks are most likely to integrate peripheral influences with central mechanisms, facilitating the precipitation of migraine headaches. These networks include sleep, feeding and stress modulating centers within the hypothalamus, thalamic pathways and brainstem centers closely involved in trigeminal pain processing such as the spinal trigeminal nucleus and the rostral ventromedial medulla, all of which are closely interconnected.

Conclusion

Taken together, these networks represent the pathophysiological basis for migraine premonitory symptoms as well as a possible integration site of peripheral so-called “triggers” with central attack facilitating processes.

The metabolic face of migraine - from pathophysiology to treatment

Migraine can be regarded as a conserved, adaptive response that occurs in genetically predisposed individuals with a mismatch between the brain's energy reserve and workload. Given the high prevalence of migraine, genotypes associated with the condition seem likely to have conferred an evolutionary advantage. Technological advances have enabled the examination of different aspects of cerebral metabolism in patients with migraine, and complementary animal research has highlighted possible metabolic mechanisms in migraine pathophysiology. An increasing amount of evidence - much of it clinical - suggests that migraine is a response to cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity and that the attack itself helps to restore brain energy homeostasis and reduces harmful oxidative stress levels. Greater understanding of metabolism in migraine offers novel therapeutic opportunities. In this Review, we describe the evidence for abnormalities in energy metabolism and mitochondrial function in migraine, with a focus on clinical data (including neuroimaging, biochemical, genetic and therapeutic studies), and consider the relationship of these abnormalities with the abnormal sensory processing and cerebral hyper-responsivity observed in migraine. We discuss experimental data to consider potential mechanisms by which metabolic abnormalities could generate attacks. Finally, we highlight potential treatments that target cerebral metabolism, such as nutraceuticals, ketone bodies and dietary interventions.