Sex and Gender Considerations in Episodic Migraine

Migraine in men

BACKGROUND

Migraine is a common primary headache disorder, less frequently affecting men than women, and often regarded as predominantly a "women's disease." Despite this, migraine in men presents with unique characteristics in terms of symptoms, treatment responses, comorbidities, and pain perception. Historically, research has focused more on migraine in women, overlooking critical male-specific aspects.

RESULTS

This review delves into the epidemiology, clinical presentation, and particular challenges of diagnosing and managing migraine in men. It addresses sex-specific triggers, hormonal influences, and comorbid conditions affecting migraine prevalence and severity in men. Additionally, the review evaluates current therapeutic strategies, underscoring the necessity for individualized approaches. Men with migraine often exhibit atypical symptoms compared to the ICHD-3 criteria and are less likely to report common associated symptoms. They also tend to have fewer psychological comorbidities, respond more favorably to pharmacological treatments, yet are less likely to seek medical support. The reasons for these sex disparities are complex, involving biological, psychosocial, and cultural factors, such as brain structural differences, differences in functional responses to painful stimuli, hormonal effects, and behavioral influences like adherence to masculine norms and stigma.

CONCLUSION

Men are underrepresented in clinical migraine research. In contrast, preclinical studies often focus solely in male animals as a result of various misconceptions. This disparity necessitates greater focus on sex-specific aspects of migraine to enhance diagnosis, treatment, and research. Addressing stigma, increasing healthcare access, and ensuring balanced sex and gender representation in future studies is crucial for a comprehensive understanding and effective management of migraine for all patients.

The Global Burden of Migraine: A 30-Year Trend Review and Future Projections by Age, Sex, Country, and Region

INTRODUCTION

Migraine is a prevalent neurological disorder causing significant disability worldwide. Despite extensive research on specific populations, comprehensive analyses of global trends are remains limited.

METHODS

We extracted incidence, prevalence, and disability-adjusted life years (DALYs) data for migraine from the Global Burden of Disease 2021 database. Trends were analyzed across regions, age groups, sexes, and sociodemographic index (SDI) using estimated annual percentage changes (EAPC). Predictive models (ARIMA) were used to forecast trends to 2050.

RESULTS

From 1990 to 2021, the global burden of migraine significantly increased: prevalence increased by 58.15%, from 732.56 million to 1.16 billion cases, and incidence increased by 42.06%. The DALYs also increased by 58.27%. There were differences between the sexes: female individuals had higher absolute rates of migraine incidence and prevalence, but male individuals exhibited a four- to five-fold more rapid increase than female individuals in these parameters. Adolescents (< 20 years old) have the fastest growth in prevalence and DALYs. Regionally, high SDI regions having the highest age-standardized rate (ASR) and low SDI regions having the lowest ASR in DALYs. East Asia and Latin America exhibited the most significant increases in migraine burden, whereas Southeast Asia exhibited the most pronounced decrease. Predictive analysis suggests prevalence will continue to rise until 2050, particularly among male individuals and adolescents.

CONCLUSIONS

The global burden of migraine has significantly escalated from 1990 to 2021, with female individuals bearing a greater burden but male individuals showing a faster growth rate. Adolescents also face a rapidly rising prevalence. Disparities across SDI regions, countries, age groups, and sexes emphasize the need for targeted public health strategies. Focused interventions are required to mitigate the growing impact of migraines on global health, particularly among male individuals and adolescents.

Correlation between 25-hydroxyvitamin D and severe headache or migraine: evidence from NHANES database

Objective

This study was formulated with the objective of elucidating the correlation between 25-hydroxyvitamin D (25(OH)D) and the occurrence of severe headache or migraine, employing a cross-sectional analytical approach.

Methods

A cross-sectional survey was conducted over two cycles involving 7,661 participants, utilizing data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2001 and 2004. A weighted logistic regression method was employed to construct a relationship model between the two variables. Subgroup analysis, adjusting for confounding factors, was performed through stratified analysis to explore the association between 25(OH)D and severe headaches or migraines. Finally, a restricted cubic spline regression (RCS) was utilized to investigate the non-linear relationship between the variables.

Results

A total of 7,661 participants were included in this study, with an overall prevalence of severe headaches or migraines of 1,576/7,661 (22.3%). The results from all models consistently indicated a significant negative correlation between serum 25(OH)D levels and the risk of severe headaches or migraines (P < 0.05). Stratified analysis revealed that in the female population (odds ratios [OR]: 0.995, 95% CI: 0.991-0.998, P = 0.001), never smokers (OR: 0.991, 95% CI: 0.985-0.997, P = 0.003), and non-drinkers (OR: 0.993, 95% CI: 0.987-0.999, P = 0.022), the risk of severe headaches or migraines decreased with increasing serum 25(OH)D concentrations. RCS results demonstrated a linear relationship between serum 25(OH)D levels and the risk of severe headaches or migraines.

Conclusion

We discovered a negative correlation between serum 25(OH)D levels and the prevalence of severe headaches or migraines, particularly in females, non-smokers, and non-hypertensive individuals. Further clinical research is necessary to confirm these findings, establish causality, and explore potential preventive and therapeutic mechanisms for migraines.

Gender-specific inflammatory burden and headache risk in youth: a NHANES analysis

BACKGROUND

Headaches are a common and often debilitating condition among youth. The Inflammatory Burden Index (IBI), a simple surrogate marker of systemic inflammation, has been linked to various diseases. However, evidence for its relationship with headaches, particularly in youth, is lacking. This study aimed to investigate the association between IBI and persistent headache in youth, with a focus on evaluating gender-specific responses to IBI exposure.

METHODS

We analyzed data from 2,210 young people in the 2001-2004 National Health and Nutrition Examination Survey (NHANES). The association between IBI and frequent or severe headaches in the past year was investigated using weighted logistic regression models. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated, and threshold effect analyses were performed.

RESULTS

Youths in the highest IBI quartile (Q4) had a 46% higher risk of severe headaches compared to the lowest quartile (Q1) (OR: 1.46, 95% CI: 1.12-1.91, P = 0.0051). Gender-stratified analysis revealed a significant association between high IBI and headache risk in females (OR: 1.48; 95% CI: 1.03-2.11, P = 0.0324), but not in males. Threshold effect analysis identified an IBI breakpoint of 3.78, below which the headache risk increased significantly in females under 18 years (OR: 1.12, 95% CI: 1.01-1.25, P = 0.0385).

CONCLUSIONS

Our findings demonstrate a significant association between elevated IBI and increased headache risk in youth, particularly in females. This gender-specific effect suggests that inflammatory processes may play a more prominent role in headache pathophysiology among female youth. These results underscore the importance of considering inflammatory markers in the early identification and prevention of youth headaches, especially in females.

Sex Differences in the Expression of Central Sensitization Symptoms in Migraine: An Observational Study

Background: Migraine is the fourth most common cause of disability in women and the eighth most common cause in men. Central sensitization phenomena predispose to chronic migraine and are generally more pronounced in women. Objective: The aim of this retrospective observational study was to look for sex differences in a population of migraine subjects attending a tertiary headache center, focusing on symptoms of central sensitization such as allodynia and pericranial tenderness. Methods: This study is based on data collected at a tertiary headache center between January 1, 2018, and December 31, 2022. The clinical interview included the main features of migraine, allodynia, a disability questionnaire, the pericranial tenderness score, and anxiety and depression scales. Results: We selected a total of 1,087 migraine subjects (233 men). Osmophobia predominated in women, as did nausea. Disability scores, headache intensity, allodynia, anxiety, and depression predominated in women, without menopausal age playing a role. The frequency of symptomatic medication use was similar in both sexes. Allodynia score was the largest discriminating factor between women and men. Conclusions: Women with migraine are more likely than men to report acute allodynia, nausea, and osmophobia and are also more likely to be anxious, depressed, and disabled. These features appear to be independent of fertile age and are probably related to sex-specific genetic characteristics. These symptoms represent a tendency toward sensory hypersensitivity and central sensitization that should be carefully assessed in both women and men with migraine with a view to possibly predicting chronic development.

The Potential Health Risks and Benefits of Progesterone in the Transgender Woman Population-A Narrative Review

INTRODUCTION

Currently, progesterone is notably absent from conventional feminizing hormone therapies for transgender women. Anecdotal reports indicate the potential for health advantages following the incorporation of progesterone into treatment regimens. The primarily female hormone, progesterone naturally surges in women during the menstrual luteal phase. When administered exogenously, it may expedite bodily changes that are pivotal for gender transition. Progesterone holds promise as a potential remedy for various health conditions prevalent in the transgender woman population.

METHODS

This narrative review synthesizes existing literature and presents a comprehensive account of the administration of exogenous progesterone in transgender women. A literature search was conducted using the PubMed, Embase, ScienceDirect, and ResearchGate databases. The following keywords were used in the search: progesterone, transgender, breast neoplasms, lactation, prostate, testicular neoplasms, and thrombosis. These terms were combined using Boolean operators. The results of the initial search were screened by three independent reviewers based on their relevance to the topic under study.

RESULTS

A total of 104 studies were initially identified as meeting the criteria for inclusion. Following an assessment based on the contents of the title, abstract, and full text, 39 studies were deemed eligible for inclusion. A critical examination of health outcomes was conducted across key sections, including breast development, mental health, lactation, cancer risk (breast and prostate), thrombosis, and nervous and other systems.

DISCUSSION

The use of progesterone in the transgender woman population is a topic that has yet to be sufficiently researched. The limited sample size, short follow-up periods, and lack of randomization restrict the potential for achieving a robust scientific evidence base. In order to gain a fuller understanding of this topic, findings from studies on contraception, hormone replacement therapy, and animal models were considered.

CONCLUSIONS

Progesterone may have a beneficial effect on the bodies of transgender women without significant adverse health effects. Further investigation through well-designed studies is recommended. Randomized controlled trials that include various dosages, broad and long-term effects, and precise demographics are needed. There is an immediate need for more knowledge to create appropriate patent and clinical practice guidelines.

Animal Models of Chronic Migraine: From the Bench to Therapy

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Headache disorders: a persistent public health challenge for the under 50s

Introduction

Currently, neurological diseases has surpassed cardiovascular diseases as the primary cause of global disease burden. Among these, headache disorders are the most prevalent and have emerged as the main cause of disability in people under 50 years old in recent years. Since the release of GBD 2021, there has been no comprehensive systematic exposition on the burden of headache among individuals under 50 years old and a forecast for future burdens. This study aims to quantify the global, regional, and national burden of headache disorders among people under 50 from 1992 to 2021 and to predict future trends in order to provide policy makers with precise and effective epidemiological evidence.

Methods

This study extracted the incidence, prevalence, and DALYs data related to headache disorders in the 5-50 age group from the GBD 2021. After age-standardizing the data, we used joinpoint regression analysis and health inequity analysis to analyze the burden and temporal trend of headache disorders and predicted the future disease burden and changes based on the age-period-cohort model.

Results

By 2021, the case number of global incidence, prevalence and DALYs have increased by 35, 39, and 41%, respectively, over the past 30 years. The incidence and prevalence of tension-type headache (TTH) are significantly higher than those of migraine, but migraine causes greater health burdens. The burden is higher for female than for male. In terms of age, youth aged 25-29 years had the highest incidence in 2021, with an age-standardized rate (ASR) of 13,454.64 (95%CI, 9,546.96-18,361.36) per 100,000 population. Nationally, the highest ASR of incidence and prevalence are found in Norway, and the most damaging to health is found in Belgium. Among the five sociodemographic index (SDI) categories, the middle SDI has the highest number of cases (190 million in 2021). It is worth noting that the forecast shows that by 2046 the three indicators will reach 680 million, 2.33 billion, and 41 million, respectively, indicating that the burden of headache disorders in this age group will continue to persist.

Conclusion

Globally, the burden of headache disorders in people under 50 years of age remains significant and has not improved over the past 30 years, especially in regions with high SDI. Headache problems will continue to pose a serious public health challenge for this age group for some time to come. This study reveals the burden and distribution of headache disorders in this age group, providing important basis for governments and policymakers to accurately and effectively allocate health care resources, strengthen prevention and management strategies, and respond to this global health problem.

Activating transcription factor 3 (ATF3) and calcitonin gene-related peptide (CGRP) increase in trigeminal ganglion neurons in female rats after photorefractive keratectomy (PRK)-like corneal abrasion

Photorefractive keratectomy (PRK) is a type of eye surgery that involves removal of the corneal epithelium and its associated nerves, which causes intense acute pain in most people. We used a rat model of corneal epithelium removal (corneal abrasion) to examine underlying cellular and molecular mechanisms. In this study, we used immunohistochemistry of trigeminal ganglion (TG) to assess neuronal content of CGRP and ATF3, as well as orbital tightening (OT) to assess spontaneous pain behaviors. CGRP is an important neuropeptide in pain modulation and ATF3 is often used as a nerve injury marker. We found dynamic changes in CGRP and ATF3 in TG; both increased significantly at 24 h following corneal abrasion and females had a more pronounced increase at 24 h compared to males. Interestingly, there was no sex difference in OT behaviors. Additionally, the number of cells containing either CGRP or ATF3 in each animal correlate significantly with their OT behavior at the assessed timepoint. Since CGRP increased most in females, we tested the effectiveness of Olcegepant, a CGRP antagonist, at reducing OT behaviors following corneal abrasion in female rats. Olcegepant (1 mg/kg) was given prior to and again at 24 h after abrasion but did not change OT behaviors at any time over a 1-week period. Examination of CGRP and ATF3 together in TG showed that they rarely colocalized, indicating that the cells with upregulated CGRP are distinct from those responding to epithelial nerve injury. The studies also show that underlying molecular responses may be sex specific.

The role of androgens in migraine pathophysiology

Migraine affects ∼12 % of the worldwide population and is more prevalent in females, which suggests a role of sex hormones in migraine pathophysiology. Most studies have focused on estrogen and progesterone, and the involvement of androgens has been less studied. However, due to the recent advances in androgen interventions, which could advance new androgen-based migraine treatments, it is critical to better understand the role of androgens in migraine. Testosterone, the most studied androgen, was found to have an antinociceptive effect in various animal and human pain studies. Thus, it could also have a protective effect related to lower migraine severity and prevalence. In this review, we discuss studies examining the role of androgens on migraine-related symptoms in migraine animal models. Additionally, we summarize the results of human studies comparing androgen levels between patients with migraine and healthy controls, studies assessing the relationships between androgen levels and migraine severity, and intervention studies examining the impact of testosterone treatment on migraine severity. Many of the studies have limitations, however, the results suggest that androgens may have a minor effect on migraine. Still, it is possible that androgens are involved in migraine pathophysiology in a sub-group of patients such as in adolescents or postmenopausal women. We discuss potential mechanisms in which testosterone, as the main androgen tested, can impact migraine. These mechanisms range from the cellular level to systems and behavior and include the effect of testosterone on sensory neurons, the immune and vascular systems, the stress response, brain function, and mood. Lastly, we suggest future directions to advance this line of research.

Global, regional, and national burden and trends of migraine among women of childbearing age from 1990 to 2021: insights from the Global Burden of Disease Study 2021

BACKGROUND

Migraine, a neurological disorder with a significant female predilection, is the leading cause of disability-adjusted life years (DALYs) in women of childbearing age (WCBA). There is currently a lack of comprehensive literature analysis on the overall global burden and changing trends of migraines in WCBA.

METHODS

This study extracted three main indicators, including prevalence, incidence, and DALYs, related to migraine in WCBA from the Global Burden of Disease(GBD) database from 1990 to 2021. Our study presented point estimates with 95% uncertainty intervals (UIs). It evaluated the changing trends in the burden of migraine in WCBA using the estimated annual percentage change (EAPC) and percentage change.

RESULTS

In 2021, the global prevalence, incidence, and DALYs cases of migraine among WCBA were 493.94 million, 33.33 million, and 18.25 million, respectively, with percentage changes of 48%, 43%, and 47% compared to 1990. Over the past 32 years, global prevalence rates and DALYs rates globally have increased, with an EAPC of 0.03 (95% UI: 0.02 to 0.05) and 0.04 (95% UI: 0.03 to 0.05), while incidence rates have decreased with an EAPC of -0.07 (95% UI: -0.08 to -0.05). Among the 5 Socio-Demographic Index (SDI) regions, in 2021, the middle SDI region recorded the highest cases of prevalence, incidence, and DALYs of migraine among WCBA, estimated at 157.1 million, 10.56 million, and 5.81 million, respectively, approximately one-third of the global total. In terms of age, in 2021, the global incidence cases for the age group 15-19 years were 5942.5 thousand, with an incidence rate per 100,000 population of 1957.02, the highest among all age groups. The total number of migraine cases and incidence rate among WCBA show an increasing trend with age, particularly in the 45-49 age group.

CONCLUSIONS

Overall, the burden of migraine among WCBA has significantly increased globally over the past 32 years, particularly within the middle SDI and the 45-49 age group. Research findings emphasize the importance of customized interventions aimed at addressing the issue of migraines in WCBA, thus contributing to the attainment of Sustainable Development Goal 3 set by the World Health Organization.

Neurological care for LGBT+ people

Sexual and gender minority (LGBT+) people face unique health disparities that must be considered by health-care providers to ensure equitable and inclusive care. Although traditionally LGBT+ health has not been integrated into neurology training, sexual orientation and gender identity have direct relevance to neurological health, driven by both systemic and interpersonal factors. In this Review, we summarize the evidence for associations between sexual orientation and gender identity with the prevalence and outcomes of various neurological conditions, including neurodegenerative diseases, epilepsy, stroke and neurodevelopmental disorders, among others. We describe important clinical considerations pertaining to LGBT+ people and recommend language and practices to promote inclusive care, as well as highlight gaps in need of further research and possible strategies to minimize these, including systematic collection of sexual orientation and gender identity and use of inclusive language.

Female-selective mechanisms promoting migraine

Sexual dimorphism has been revealed for many neurological disorders including chronic pain. Prelicinal studies and post-mortem analyses from male and female human donors reveal sexual dimorphism of nociceptors at transcript, protein and functional levels suggesting different mechanisms that may promote pain in men and women. Migraine is a common female-prevalent neurological disorder that is characterized by painful and debilitating headache. Prolactin is a neurohormone that circulates at higher levels in females and that has been implicated clinically in migraine. Prolactin sensitizes sensory neurons from female mice, non-human primates and humans revealing a female-selective pain mechanism that is conserved evolutionarily and likely translationally relevant. Prolactin produces female-selective migraine-like pain behaviors in rodents and enhances the release of calcitonin gene-related peptide (CGRP), a neurotransmitter that is causal in promoting migraine in many patients. CGRP, like prolactin, produces female-selective migraine-like pain behaviors. Consistent with these observations, publicly available clinical data indicate that small molecule CGRP-receptor antagonists are preferentially effective in treatment of acute migraine therapy in women. Collectively, these observations support the conclusion of qualitative sex differences promoting migraine pain providing the opportunity to tailor therapies based on patient sex for improved outcomes. Additionally, patient sex should be considered in design of clinical trials for migraine as well as for pain and reassessment of past trials may be warranted.

The prevalence and demographic associations of headache in the adult population of Benin: a cross-sectional population-based study

BACKGROUND

The Global Burden of Disease (GBD) study is increasingly well informed with regard to headache disorders, but sub-Saharan Africa (SSA) remains one of the large regions of the world with limited data directly derived from population-based studies. The Global Campaign against Headache has conducted three studies in this region: Ethiopia in the east, Zambia in the south and Cameroon in Central SSA. Here we report a similar study in Benin, the first from West SSA.

METHODS

We used the same methods and questionnaire, applying cluster-randomized sampling in three regions of the country, randomly selecting households in each region, visiting these unannounced and randomly selecting one adult member (aged 18-65 years) of each household. The HARDSHIP structured questionnaire, translated into Central African French, was administered face-to-face by trained interviewers. Demographic enquiry was followed by diagnostic questions based on ICHD-3 criteria.

RESULTS

From 2,550 households with eligible members, we recruited 2,400 participants (participating proportion 94.1%). Headache ever was reported by almost all (95.2%), this being the lifetime prevalence. Headache in the last year was reported by 74.9%. Age-, gender- and habitation-adjusted estimates of 1-year prevalence were 72.9% for all headache, 21.2% for migraine (including definite and probable), 43.1% for TTH (also including definite and probable), 4.5% for probable medication-overuse (pMOH) and 3.1% for other headache on ≥ 15 days/month. One-day (point) prevalence of headache was 14.8% according to reported headache on the day preceding interview.

CONCLUSIONS

Overall, these findings are evidence that headache disorders are very common in Benin, a low-income country. The prevalence of pMOH, well above the estimated global mean of 1-2%, is evidence that poverty is not a bar to medication overuse. The findings are very much the same as those in a similar study in its near neighbour, Cameroon. With regard to migraine, they are reasonably in accord with two of three earlier studies in selected Beninese populations, which did not take account of probable migraine. This study adds to the hitherto limited knowledge of headache in SSA.

Neurological Health in Sexual and Gender Minority Individuals

Despite representing a significant proportion of the U.S. population, there is a paucity of population-based research on the health status and health needs of sexual and gender minority (SGM) individuals in neurology. Compared with heterosexual peers, some SGM populations have a higher burden of chronic health conditions. In parallel, SGM individuals are more likely to experience stigma and discrimination producing psychological distress, which may contribute to and be compounded by reduced health care access and utilization. In this narrative review, we summarize the existing literature on common neurological health conditions such as stroke, headache, epilepsy, movement disorders, and traumatic brain injury through the lens of intersection of SGM identity. Special focus is attuned to social determinants of health and gender-affirming hormonal therapy. Given the limitations in the available literature, there is an urgent unmet need for datasets that include sexual orientation and gender identity information, as well as funding for research that will characterize the prevalence of neurological conditions, unique risk factors, and health outcomes in SGM populations. In the health care community, providers should address deficiencies in their professional training and integrate inclusive language into their clinical skillset to build trust with SGM patients. There is an opportunity in neurology to proactively engage SGM communities, collaborate to remove barriers to care, promote resilience, and develop targeted interventions to ensure high-quality, culturally competent care for SGM populations to improve neurological health for all.

[Gender-specific results of the Dresden children and adolescents headache program DreKiP]

BACKGROUND

Girls and women are more frequently affected by headache than boys and men. The influence of gender on the effectiveness of headache therapies has so far been hardly investigated. We examined gender differences in the outpatient multimodal Dresden Child and Adolescent Headache Program DreKiP.

METHODS

We treated 140 patients with primary headache in a 15-hour structured group program. At baseline (T0) and six (T1) and twelve months (T2) after the end of the program, data on headache-related limitation of daily activities (PedMIDAS) as well as headache frequency, intensity, and pain-related disability (P-PDI) were collected. Retrospectively, these data were analyzed separately for girls and boys.

RESULTS

For 91 patients (9-19 years, median = 15; 71.4 % female) data were available for at least two measurement time points. Girls showed significantly higher headache frequency than boys at all time points (median headache days/last three months at T0: ♀ 43, ♂ 20; T1: ♀ 32, ♂ 12; T2: ♀ 28, ♂ 9) as well as numerically higher headache-related limitation of daily life. There were significant effects over time with a decrease in headache frequency (F (2.88) = 5.862; p = 0.004) and improvement in daily functioning (F (2.92) = 5.340; p = 0.006). There was no gender-specific treatment response.

DISCUSSION

The DreKiP therapy shows effects in girls and boys with primary headache. Higher headache frequencies and everyday life restrictions in girls may have hormonal but also psychosocial causes and should be addressed in educational measures.

Evaluation of outcomes of calcitonin gene-related peptide (CGRP)-targeting therapies for acute and preventive migraine treatment based on patient sex

BACKGROUND

Women show increased prevalence and severity of migraine compared to men. Whether small molecule calcitonin gene-related peptide receptor (CGRP-R) antagonists (i.e., gepants) and monoclonal antibodies targeting either the CGRP-R or the CGRP peptide might show sexually dimorphic outcomes for acute and preventive therapy has not been established.

METHODS

We conducted a subpopulation analysis of available published data from FDA reviews to evaluate potential sex differences in the response rates of ubrogepant, rimegepant and zavegepant for acute migraine therapy. Available data from FDA reviews of erenumab, fremanezumab, galcanezumab and eptinezumab, approved CGRP-R and CGRP monoclonal antibodies and of atogepant were examined for prevention outcomes based on patient sex. Preventive outcomes were analyzed separately for patients with episodic migraine and chronic migraine.

RESULTS

In women, the three approved gepants produced statistically significant drug effects regardless of dose tested on the FDA mandated co-primary endpoints, the proportion of patients achieving two-hour pain-freedom and the proportion of patients free of their most bothersome symptom at two hours post-dose. In women, the average placebo-subtracted two-hour pain-freedom proportion was 9.5% (CI: 7.4 to 11.6) and the average numbers needed to treat was 11. The free from most bothersome symptom at two hours outcomes were also significant in women. The gepant drugs did not reach statistically significant effects on the two-hour pain-freedom endpoint in the men, with an average drug effect of 2.8% (CI: -2.5 to 8.2) and an average number needed to treat of 36. For freedom from most bothersome symptom at two hours post-dose endpoint, differences were not significant in male patients. The treatment effect in each of the gepant studies was always numerically greater in women than in men. In evaluation of prevention outcomes with the antibodies or atogepant using the change from the specified primary endpoint (e.g., monthly migraine days), the observed treatment effect for episodic migraine patients almost always favored drug over placebo in both women and men. For chronic migraine patients the treatment effects of antibodies were similar in men and women and always favored the drug treated group.Conclusion/Interpretation: Small molecule CGRP-R antagonists are effective in acute migraine therapy in women but available data do not demonstrate effectiveness in men. CGRP-targeting therapies are effective for migraine prevention in both male and female episodic migraine patients but possible sex differences remain uncertain. In male and female chronic migraine patients, CGRP/CGRP-R antibodies were similarly effective. The data highlight possible differential effects of CGRP targeted therapies in different patient populations and the need for increased understanding of CGRP neurobiology in men and women.

Assessment of Preferences in Taking Painkillers among Students of Medicine, Dentistry, and Pharmacy: A Pilot Study

Students of pharmacy, medicine, and dentistry are important for shaping drug policy. The aim of this study is to assess and compare students preferences in taking painkillers. The study group consists of 382 students of pharmacy (28.8%), medicine (40.0%), and dentistry (30.1%). An anonymous questionnaire consisting of 17 questions was prepared using the Google Forms platform and distributed through social media. Ibuprofen was the most frequently preferred, regardless of the study major (57.8%). Pharmacy students expressed the least concern about the possible side effects of analgesics (17.5%). The fast onset of painkillers was more important for dental students (59.1%) and pharmacy students (44.7%), compared to medical students (39.22%). Medicine and pharmacy students indicated their studies to be their main source of information about painkillers compared to dentistry students (p = 0.001). There are no differences in pain severity regarding which analgesics are used among student groups (p = 0.547). Dental students experienced odontogenic pain less frequently (57.3%) than medical (79.7%) and pharmacy students (79.8%), (p = 0.000). Ketoprofen was the most frequently chosen prescription painkiller for odontogenic pain in all groups (49.4%). Gastrointestinal complaints were the most often reported side effects, regardless of the study major (87.1%). Choice of studies, gender, and year of study were the most important determinants of the choice of painkillers.

Trends in migraine incidence among women of childbearing age from 1990 to 2019 and the prediction for 2030: an analysis of national data in China

BACKGROUND

Migraine is a primary headache, which has been producing heavy disease burden globally. There is no data on the incidence of migraine among women of childbearing age worldwide, including China. This study aimed to investigate the time trend in incidence rate of migraine among women of childbearing age in China from 1999 to 2019, and to make a prediction for 2030.

METHODS

Data on migraine incidence and population among women of childbearing age in China were derived from the Global Burden of Diseases Study 2019. Crude and age-standardized incidence rates of migraine (CIR, ASIR) were presented. The trend in migraine during 1990-2019 was examined using annual percent change and average annual percent change based on Joinpoint regression models. Age-period-cohort model was introduced to estimate the independent effect of age, period and cohort on migraine incidence rate among participants over the three decades. Bayesian age-period-cohort analysis was conducted to predict migraine incidence rate for 2030 among women of childbearing age in China.

RESULTS

For women of childbearing age in China, the case number, CIR and ASIR of migraine kept rising, with a cumulative percentage increase of 10.87%, 2.01% and 5.65%, respectively, from 1990 to 2019. An annual percent increase of 0.18% in the ASIR was observed over the three decades. As for the age, period and cohort effects, the adjusted cohort-specific relative risks constantly increased from 0.91 (95% CI: 0.90, 0.93) in the 1940-1949 cohort to 1.04 (95% CI: 1.03, 1.05) in the 1995-2004 cohort, while the period-specific relative risks initially declined from 1.00 (95% CI: 0.99, 1.00) in 1990-1994 cohort to 0.99 (95% CI: 0.98, 0.99) in 1995-1999 cohort, and then increased to 1.04 (95% CI: 1.03, 1.04) in 2015-2019 cohort. Moreover, the age-specific relative risks of migraine followed a bimodal pattern with peaks at the age-group of 25-29 years (CIR = 1718.27/100000) and 35-39 years (CIR = 1635.18/100000). Projection modeling showed that the CIR and ASIR of migraine will continue to significantly increase from 2020 to 2030.

CONCLUSION

Migraine incidence remained an increasing trend from 1990 to 2019 and is projected to continually increase till 2030 among women of childbearing age in China. This study has important public health implication for population-level migraine prevention in China. Precision intervention strategies and approaches shall be considered in campaigns initiated for migraine prevention among Chinese women of childbearing age.

Headache disorders and relevant sex and socioeconomic patterns in adolescents and young adults across 204 countries and territories: an updated global analysis

BACKGROUND

Primary headache disorders are a group of highly prevalent and disabling neurological diseases that mainly consist of migraine and tension-type headache (TTH). A previous study showed that the burden of headaches peaked at a working age that ranged from 15 to 49, particularly among females, affecting their productivity and severely damaging their social interactions.

METHODS

The latest dataset was retrieved from the Global Burden of Disease (GBD) Study 2019. Three indicators, including prevalence, incidence, and years lived with disability (YLDs), were adopted for evaluation. The overall and specific headache burdens were fully compared and analysed at global, regional, and national levels. The ratio of female YLD rates to male YLD rates due to headaches was calculated to estimate the sex pattern. Finally, we utilized the two-tailed Spearman test to explore the potential association between socioeconomic background and headaches among young people.

RESULTS

Globally, for overall headache disorders, a total of 2,049,979,883 prevalent cases (95% uncertainty interval (UI): 1,864,148,110 to 2,239,388,034), 601,229,802 incident cases (95% UI: 530,329,914 to 681,007,934), and 38,355,993 YLDs (95% UI: 7,259,286 to 83,634,503) were observed for those aged 10 to 54 in 2019. Sex differences were widely found for all headache types among adolescents and young adults, especially migraine. However, the most interesting finding was that the associations we tested between the socioeconomic environment and young headache patients were positive, regardless of region or specific country or territory.

CONCLUSIONS

Overall, the global burden of headaches in adolescents and young adults largely increased from 1990 to 2019. Although slight declines were observed in sex differences, they remained significant and challenging. The positive correlations between headache and socioeconomic background among young people were relatively inconsistent with previous investigations, and several related hypotheses were proposed for explanation. Interdisciplinary actions involving education, policy- and law-making, and basic medical practice are desperately needed to further fight against the headache burden, promote gender equality in headache care, and eliminate the stigmatization of headache patients in student and working groups.

Medication Overuse Headache: an Updated Review and Clinical Recommendations on Management

OVERVIEW

Medication overuse headache (MOH) is highly prevalent among individuals with primary headache disorders.

PURPOSE OF REVIEW

(1) Provide an update on epidemiology, risk factors, and treatment strategies of MOH and (2) provide recommendations on the management of MOH.

RECENT FINDINGS

The prevalence of MOH ranges from 0.5 to 7.2%. Risk factors for MOH include female sex, lower socioeconomic status, some psychiatric conditions, and substance use disorders, among others. Recent large clinical trials support preventative therapy as an integral component of MOH management. Emerging clinical trial evidence supports anti-CGRP mAbs as effective preventative treatments among individuals with migraine and MOH. Among the large clinical trials, candesartan, topiramate, amitriptyline, and onabotulinumtoxinA were the most used preventative therapies, providing further support for these agents. MOH management requires a multifaceted and patient-centered approach that involves patient education, behavioral interventions, withdrawal of the overused medication, and initiation of preventative medication.

Endogenous Inflammatory Mediators Produced by Injury Activate TRPV1 and TRPA1 Nociceptors to Induce Sexually Dimorphic Cold Pain That Is Dependent on TRPM8 and GFRα3

The detection of environmental temperatures is critical for survival, yet inappropriate responses to thermal stimuli can have a negative impact on overall health. The physiological effect of cold is distinct among somatosensory modalities in that it is soothing and analgesic, but also agonizing in the context of tissue damage. Inflammatory mediators produced during injury activate nociceptors to release neuropeptides, such as calcitonin gene-related peptide (CGRP) and substance P, inducing neurogenic inflammation, which further exasperates pain. Many inflammatory mediators induce sensitization to heat and mechanical stimuli but, conversely, inhibit cold responsiveness, and the identity of molecules inducing cold pain peripherally is enigmatic, as are the cellular and molecular mechanisms altering cold sensitivity. Here, we asked whether inflammatory mediators that induce neurogenic inflammation via the nociceptive ion channels TRPV1 (vanilloid subfamily of transient receptor potential channel) and TRPA1 (transient receptor potential ankyrin 1) lead to cold pain in mice. Specifically, we tested cold sensitivity in mice after intraplantar injection of lysophosphatidic acid or 4-hydroxy-2-nonenal, finding that each induces cold pain that is dependent on the cold-gated channel transient receptor potential melastatin 8 (TRPM8). Inhibition of CGRP, substance P, or toll-like receptor 4 (TLR4) signaling attenuates this phenotype, and each neuropeptide produces TRPM8-dependent cold pain directly. Further, the inhibition of CGRP or TLR4 signaling alleviates cold allodynia differentially by sex. Last, cold pain induced by both inflammatory mediators and neuropeptides requires TRPM8, as well as the neurotrophin artemin and its receptor GDNF receptor α3 (GFRα3). These results are consistent with artemin-induced cold allodynia requiring TRPM8, demonstrating that neurogenic inflammation alters cold sensitivity via localized artemin release that induces cold pain via GFRα3 and TRPM8.SIGNIFICANCE STATEMENT The cellular and molecular mechanisms that generate pain are complex with a diverse array of pain-producing molecules generated during injury that act to sensitize peripheral sensory neurons, thereby inducing pain. Here we identify a specific neuroinflammatory pathway involving the ion channel TRPM8 (transient receptor potential cation channel subfamily M member 8) and the neurotrophin receptor GFRα3 (GDNF receptor α3) that leads to cold pain, providing select targets for potential therapies for this pain modality.

Disease burden of migraine and tension-type headache in non-high-income East and Southeast Asia from 1990 to 2019

BACKGROUND

The world faces severe challenges from migraine and tension-type headache (TTH), which cause grave disability to patients and place a heavy burden on their caregivers. However, headaches in specific individual regions have rarely been investigated. Therefore, we aimed to fully analyse and describe the current status and changing trends in migraine and TTH in non-high-income East and Southeast Asia to provide more detailed real-world information for policy-making.

METHODS

The migraine and TTH data used for analysis were all extracted from the Global Burden of Disease (GBD) database. We adopted three major indicators of disease burden, including prevalence, incidence, and years lived with disability (YLD), and two major metrics, including the absolute number and the age-standardized rate, in our present study for further evaluation by age and sex. The results are presented in the form of mean values and 95% uncertainty intervals (UIs). In addition, the differences between non-high-income East and Southeast Asia and other regions, as well as the potential associations between headache burden and socioeconomic background, were explored.

RESULTS

In 2019, approximately 195,702,169 migraine patients and 291,924,564 TTH patients lived in non-high-income East Asia, and 113,401,792 migraine patients and 179,938,449 TTH patients lived in non-high-income Southeast Asia. In terms of specific countries and regions, the highest age-standardized YLD rate (ASYR) of migraine was in Thailand [645 (95% UI: 64 to 1,554)]. The highest ASYR of TTH was in Indonesia [54 (95% UI: 15 to 197)]. Furthermore, people between the ages of 40 and 44, especially females, were identified as the main population that suffered from migraine and TTH. Unfortunately, we did not observe a significant association between headache burden and socioeconomic background.

CONCLUSIONS

To date, the threats from migraine and TTH in non-high-income East and Southeast Asia are still serious and ongoing, leading to prominently negative impacts on the daily life and work of local residents. Therefore, full attention and sound guidelines are urgently needed to obtain greater advantages in fighting against the burden of headache disorders in the future.

Endogenous inflammatory mediators produced by injury activate TRPV1 and TRPA1 nociceptors to induce sexually dimorphic cold pain that is dependent on TRPM8 and GFRα3

The detection of environmental temperatures is critical for survival, yet inappropriate responses to thermal stimuli can have a negative impact on overall health. The physiological effect of cold is distinct among somatosensory modalities in that it is soothing and analgesic, but also agonizing in the context of tissue damage. Inflammatory mediators produced during injury activate nociceptors to release neuropeptides, such as CGRP and substance P, inducing neurogenic inflammation which further exasperates pain. Many inflammatory mediators induce sensitization to heat and mechanical stimuli but, conversely, inhibit cold responsiveness, and the identity of molecules inducing cold pain peripherally is enigmatic, as are the cellular and molecular mechanisms altering cold sensitivity. Here, we asked if inflammatory mediators that induce neurogenic inflammation via the nociceptive ion channels TRPV1 and TRPA1 lead to cold pain in mice. Specifically, we tested cold sensitivity in mice after intraplantar injection of lysophosphatidic acid (LPA) or 4-hydroxy-2-nonenal (4HNE), finding each induces cold pain that is dependent on the cold-gated channel TRPM8. Inhibition of either CGRP, substance P, or toll-like receptor 4 (TLR4) signaling attenuates this phenotype, and each neuropeptide produces TRPM8-dependent cold pain directly. Further, the inhibition of CGRP or TLR4 signaling alleviates cold allodynia differentially by sex. Lastly, we find that cold pain induced by inflammatory mediators and neuropeptides requires the neurotrophin artemin and its receptor GFRα3. These results demonstrate that tissue damage alters cold sensitivity via neurogenic inflammation, likely leading to localized artemin release that induces cold pain via GFRα3 and TRPM8.

Significance Statement

The cellular and molecular mechanisms that generate pain are complex with a diverse array of pain-producing molecules generated during injury that act to sensitize peripheral sensory neurons, thereby inducing pain. Here we identify a specific neuroinflammatory pathway involving the ion channel TRPM8 and the neurotrophin receptor GFRα3 that leads to cold pain, providing select targets for potential therapies for this pain modality.