Weather, ambient air pollution, and risk of migraine headache onset among patients with migraine

Elevation in body temperature may increase susceptibility to cortical spreading depression in a rat model

One characteristic of migraine is recurrent headache attacks, which are known to be induced by changes in climatic variables such as atmospheric pressure, humidity, and outside temperature. However, the relationship between temperature changes and migraine remains unclear. Therefore, we investigated the relationship between body temperature changes and cortical spreading depression (CSD) using KCl-induced rat models of CSD. We initially induced CSD under controlled conditions at a room temperature of 28°C on an operating table maintained at 37°C. Subsequently, we controlled the operating table temperature to induce a second round of CSD under conditions of either a 10 ± 1% increase or decrease in body temperature. We ensured 1 h rest period between the first and second inductions of CSD. The results indicated that the number of CSDs significantly increased after body temperature elevation (before, 8.8 ± 1.2 times vs. after, 13.4 ± 1.3 times; p = 0.0003). The mean percentage change in cerebral blood flow decreased after body temperature increased (before, 33.1 ± 2.4% vs. after, 18.2 ± 1.4%; p = 0.006). There were no significant changes in CSD after body temperature decreased. The susceptibility of the cortex to CSD may increase under conditions of elevated body temperature.

Estimating the Acute Health Effects of Smoke Exposure from an Urban Factory Fire Accident: A Case Study of a Tire Factory Fire in Korea

BACKGROUND

A major industrial fire accident occurred in a tire manufacturing factory in Daejeon, Korea, on 12 March 2023 and lasted for 3 d, generating air pollutant emissions. Although evidence regarding the health effects of urban fires is limited, residents near tire factory may have experienced health hazards due to smoke exposure from fire plumes.

OBJECTIVES

Capitalizing on the timing of this fire incident as a natural experiment, we estimated the attributable excess air pollution exposure and associated disease development among residents living near the tire factory.

METHODS

We used the generalized synthetic control method to estimate air pollution exposure and health burden attributable to the accident among residents living in smoke-exposed districts. Based on satellite images and air pollution monitoring results, three administrative districts (within 1.2 km from the factory) were defined as smoke-exposed, and the other 79 districts of Daejeon were defined as controls. Among the 11 monitoring stations in Daejeon, the station located 500 m from the factory was used to estimate excess air pollution exposure (PM 10 , PM 2.5 , NO 2 , O 3 , SO 2 , and CO) for residents in the exposed districts. The number of daily district-level disease-specific incidence cases were acquired from the National Health Insurance Database and used to estimate excess health burden resulting from the fire.

RESULTS

During the first week following the factory fire, residents of exposed districts had an estimated excess exposure to 125.2 [95% confidence interval (CI): 44.9, 156.7] μ g / m 3 of PM 10 , 50.4 (95% CI: 12.7, 99.8) ppb of NO 2 , and 32.0 (95% CI: 21.0, 35.9) ppb of SO 2 . We also found an average increase in the incidence cases of other diseases of upper respiratory tract [20.6 persons (95% CI: 6.2, 37.4)], lung disease due to external agents [2.5 persons (95% CI: 2.1, 3.3)], urticaria and erythema [5.9 persons (95% CI: - 0.6 , 11.2)], and episodic and paroxysmal disorders [8.5 persons (95% CI: 3.7, 13.4)] in exposed districts.

DISCUSSION

Excessive air pollution exposure and disease incidence were identified among residents living close to the tire factory. Preventive measures, such as a warning system, to avoid health impacts to people breathing fire-related pollution may be beneficial for communities impacted by such events. https://doi.org/10.1289/EHP14115.

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.

The Environment and Headache: a Narrative Review

PURPOSE OF REVIEW

In this narrative review, we summarize the peer-reviewed literature published between 2017 and 2022 that evaluated ambient environmental risk factors for primary headache disorders, which affect more than half of the population globally. Primary headache disorders include migraine, tension-type headache (TTH), and trigeminal and autonomic cephalalgias (TAC).

RECENT FINDINGS

We identified 17 articles that met the inclusion criteria via PubMed or Google Scholar. Seven studies (41%) relied on data from US populations. The remaining studies were conducted in China, Taiwan, Germany, Ghana, Japan, the Netherlands, South Korea, and Turkey. Air pollution was the most frequently assessed environmental risk factor. Most studies were cross-sectional and focused on all-cause or migraine headaches; one study included TTH, and none included TAC. Short-term exposure to fine particulate matter (PM2.5) was not consistently associated with headache endpoints, but long-term exposure to PM2.5 was associated with migraine headache prevalence and severity across multiple studies. Elevated ambient temperature, changes in weather, oil and gas well exposure, and less natural greenspace, but not noise pollution, were also associated with headache. No studies considered water pollution, metal exposure, ultrafine particulate matter, or wildfire smoke exposure. There is a need for ongoing research focused on headache and the environment. Study designs with the greatest explanatory power may include longitudinal studies that capture the episodic nature of headache and case-crossover analysis, which control for time-invariant individual-level confounders by design. There is also a clear need for research that considers comorbid psychiatric illness and socioeconomic position as powerful modifiers of the effect of the environment on headache.

Whether Weather Matters with Migraine

PURPOSE OF REVIEW

Many patients with migraine report their attacks are triggered by various weather anomalies. Studies have shown mixed results regarding the association of migraine to weather changes. The purpose of the current review is to compile the most up-to-date research studies on how weather may affect migraine. In addition, we explore the association between weather and other inflammatory disease states as well as neurotransmitters.

RECENT FINDINGS

Migraine attacks can be related to weather variables such as barometric pressure, humidity, and wind. However, the results of recent studies are inconsistent; weathers' effect on migraine attacks is around 20%. However, very strong weather factors have a more significant effect on migraine attack variables. Many individuals identify weather as a migraine attack trigger, yet we see no causative relationship between weather and migraine patterns. The outcomes of studies indicate mixed results and reflect individual variation in how weather can impact migraine patterns. Similar relationships can be seen with other rheumatologic and pain conditions in general. Overall, the combination of weather plus other factors appears to be a more significant migraine trigger.

The association between ambient air pollution and migraine: a systematic review

Some studies have shown the effect of air pollution on migraine. However, it needs to be confirmed in larger-scale studies, as scientific evidence is scarce regarding the association between air pollution and migraine. Therefore, this systematic review aims to determine whether there are associations between outdoor air pollution and migraine. A literature search was performed in Scopus, Medline (via PubMed), EMBASE, and Web of Science. A manual search for resources and related references was also conducted to complete the search. All observational studies investigating the association between ambient air pollution and migraine, with inclusion criteria, were entered into the review. Fourteen out of 1417 identified articles met the inclusion criteria and entered the study. Among the gaseous air pollutants, there was a correlation between exposure to nitrogen dioxide (NO2) (78.3% of detrimental relationships) and carbon monoxide (CO) (68.0% of detrimental relationships) and migraine, but no apparent correlation has been found for sulfur dioxide (SO2) (21.2% of detrimental relationships) and ozone (O3) (55.2% of detrimental relationships). In the case of particulate air pollutants, particulate matter with a diameter of 10 μm or less (PM10) (76.0% of detrimental relationships) and particulate matter with a diameter of 2.5 μm or less (PM2.5) (61.3% of detrimental relationships) had relationships with migraine. In conclusion, exposure to NO2, CO, PM10, and PM2.5 is associated with migraine headaches, while no conclusive evidence was found to confirm the correlation between O3 and SO2 with migraine. Further studies with precise methodology are recommended in different cities around the world for all pollutants with an emphasis on O3 and SO2.

Spatiotemporal distribution of migraine in China: analyses based on baidu index

BACKGROUND

In recent years, innovative approaches utilizing Internet data have emerged in the field of syndromic surveillance. These novel methods aim to aid in the early prediction of epidemics across various scenarios and diseases. It has been observed that these systems demonstrate remarkable accuracy in monitoring outbreaks even before they become apparent in the general population. Therefore, they serve as valuable complementary tools to augment existing methodologies. In this study, we aimed to investigate the spatiotemporal distribution of migraine in China by leveraging Baidu Index (BI) data.

METHODS

Migraine-related BI data from January 2014 to December 2022 were leveraged, covering 301 city-level areas from 31 provincial-level regions by using the keyword "migraine ()". Prevalence data from the Global Burden of Disease study (GBD) were attracted to ensure the reliability of utilizing migraine-related BI data for research. Comprehensive analytical methods were then followed to investigate migraine's spatiotemporal distribution. The Seasonal-Trend decomposition procedure based on Loess (STL) was used to identify the temporal distribution. Spatial distribution was explored using the Getis-Ord Gi* statistic, standard deviation ellipse analysis, Moran's Index, and Ordinary Kriging. The top eight migraine-related search terms were analyzed through the Demand Graph feature in the Baidu Index platform to understand the public's concerns related to migraine.

RESULTS

A strong association was observed between migraine-related BI and the prevalence data of migraine from GBD with a Spearman correlation coefficient of 0.983 (P = 4.96 × 10- 5). The overall trend of migraine-related BI showed a gradual upward trend over the years with a sharp increase from 2017 to 2019. Seasonality was observed and the peak period occurred in spring nationwide. The middle-lower reaches of the Yangtze River were found to be hotspots, while the eastern coastal areas had the highest concentration of migraine-related BI, with a gradual decrease towards the west. The most common search term related to migraine was "How to treat migraine quickly and effectively ()".

CONCLUSIONS

This study reveals important findings on migraine distribution in China, underscoring the urgent need for effective prevention and management strategies.

Migraine and air pollution: A systematic review

OBJECTIVE

To systematically synthesize evidence from a broad range of studies on the association between air pollution and migraine.

BACKGROUND

Air pollution is a ubiquitous exposure that may trigger migraine attacks. There has been no systematic review of this possible association.

METHODS

We searched for empirical studies assessing outdoor air pollution and any quantified migraine outcomes. We included short- and long-term studies with quantified air pollution exposures. We excluded studies of indoor air pollution, perfume, or tobacco smoke. We assessed the risk of bias with the World Health Organization's bias assessment instrument for air quality guidelines.

RESULTS

The final review included 12 studies with over 4,000,000 participants. Designs included case-crossover, case-control, time series, and non-randomized pre-post intervention. Outcomes included migraine-related diagnoses, diary records, medical visits, and prescriptions. Rather than pooling the wide variety of exposures and outcomes into a meta-analysis, we tabulated the results. Point estimates above 1.00 reflected associations of increased risk. In single-pollutant models, the percent of point estimates above 1.00 were carbon monoxide 5/5 (100%), nitrogen dioxide 10/13 (78%), ozone 7/8 (88%), PM2.5 13/15 (87%), PM10 2/2 (100%), black carbon 0/1 (0%), methane 4/6 (75%), sulfur dioxide 3/5 (60%), industrial toxic waste 1/1 (100%), and proximity to oil and gas wells 6/13 (46%). In two-pollutant models, 16/17 (94%) of associations with nitrogen dioxide were above 1.00; however, more than 75% of the confidence intervals included the null value. Most studies had low to moderate risks of bias. Where differences were observed, stronger quality articles generally reported weaker associations.

CONCLUSIONS

Balancing the generally strong methodologies with the small number of studies, point estimates were mainly above 1.00 for associations of carbon monoxide, nitrogen dioxide, ozone, and particulate matter with migraine. These results were most consistent for nitrogen dioxide.

Associations between migraine and possible risk factors in the Czech Republic

Introduction

Migraine is a widespread neurological disorder, growing increasingly common. However, the pathogenesis of the disease is often unclear and the evidence for the role of various risk factors is limited. This study aimed to identify risk factors associated with migraine and to contribute towards a better understanding of this disease.

Methods

Data from 3,247 questionnaires were analyzed for associations between migraine and sex, age, BMI, degree of education, and air pollution, along with other factors such as contact with friends, physical condition, health, anxiety, and depression. A cross-sectional study was conducted with an approximately equal distribution of the sample by age, gender and two analysed regions. Data were presented using basic descriptive statistics using the chi-square test. The model output was presented using a crude odds ratio (OR) and a fully adjusted OR. Three hundred and eight-six individuals (12%) suffered from migraine.

Results

In an adjusted model, the presented study found associations between the prevalence of migraine and sex, age, and level of education. Individuals with migraine statistically significantly more often suffered from depression, anxiety and other selected factors. However, the assumed significant association between the occurrence of migraine and pollution in the region has not been found.

Clinical Characteristics and Risk Factors for Allergic Rhinitis in Children with Epistaxis

Background

Epistaxis is frequently observed in children with allergic rhinitis. However, few studies have addressed the clinical characteristics and risk factors for allergic rhinitis in children with epistaxis. This study aimed to describe the factors associated with allergic rhinitis in children with epistaxis.

Methods

In total, we recruited 80 children (aged 3-14 years) who presented with epistaxis at a tertiary hospital between January 2014 and January 2022. The follow-up duration was at least 3 months, and we performed a multivariate logistic regression analysis to identify the risk factors for allergic rhinitis.

Results

Among the 80 children examined, 57 (71.25%) had allergic rhinitis. Epistaxis mainly occurred in autumn in children with allergic rhinitis; in contrast, it mostly occurred in summer in children without it (P = 0.029). Mites are common allergens for allergic rhinitis in children with epistaxis; the univariate analysis revealed significant differences between allergic-rhinitis group and nonallergic-rhinitis group in the number of allergens (P  <  0.001) and total IgE (P  <  0.001). The difference in severity of nasal symptoms between the two groups was statistically significant and included nasal obstruction (P  <  0.001), rhinorrhea (P  <  0.001), sneezing (P  <  0.001), and nasal itching (P  <  0.001). After adjusting for potential confounders, the severity of rhinorrhea symptoms was found to be associated with an increased risk of allergic rhinitis in children with epistaxis (odds ratio: 3.86; 95% confidence interval: 1.61-9.26; P = 0.003).

Conclusions

Observing the onset season, number of allergens, total IgE, and nasal symptoms in cases of epistaxis could suggest the presence of associated allergic rhinitis and reduce the number of missed diagnoses; antiallergic drugs could help control epistaxis in these cases.

Rising trends in the burden of migraine and tension-type headache among adolescents and young adults globally, 1990 to 2019

BACKGROUND

Headache disorders are major contributors to disability in adolescents and young adults worldwide. We aimed to analyze global trends in the burden of migraine and tension-type headache in 10 to 24-year-olds from 1990 to 2019.

METHODS

Data were obtained from the Global Burden of Disease Study (GBD) 2019 to examine trends in incidence, prevalence, and disability-adjusted life years (DALYs) for migraine and tension-type headache in adolescents and young adults by location, age, sex and sociodemographic index (SDI). Joinpoint regression analyzed trends and identified years of significant change.

RESULTS

Globally, migraine and tension-type headache incidence, prevalence, and DALYs increased from 1990 to 2019, though with some fluctuations. The highest growth in migraine incidence occurred in males and individuals aged 10-14, while for tension-type headache incidence, it was observed in males and individuals aged 20-24. Prevalence and DALYs were highest for both disorders in females and those aged 20-24 years. Incidence increased fastest in East Asia for migraine and tension-type headache. For migraine, Tropical Latin America had the fastest increase in prevalence and DALYs. East Asia had the fastest increase in prevalence of tension-type headache, while North Africa and the Middle East had the highest growth in DALYs. Some high-income countries such as Singapore, Norway, and Iran (Islamic Republic of) demonstrated fast increases, while a few countries including Qatar, Thailand and Ethiopia decreased.

CONCLUSIONS

The incidence, prevalence and disability from migraine and tension-type headache are rising in adolescents and young adults, especially in males, older youth and middle SDI populations. The increasing trends highlight the need for targeted interventions focused on prevention and control in priority populations. Continued monitoring of trends can help identify strategies to promote headache health and reduce the life-course impacts of headache disorders globally.

Global, regional, and national time trends in incidence for migraine, from 1990 to 2019: an age-period-cohort analysis for the GBD 2019

BACKGROUND

The majority of epidemiological studies on migraine have been conducted in a specific country or region, and there is a lack of globally comparable data. We aim to report the latest information on global migraine incidence overview trends from 1990 to 2019.

METHODS

In this study, the available data were obtained from the Global Burden of Disease 2019. We present temporal trends in migraine for the world and its 204 countries and territories over the past 30 years. Meanwhile, an age-period-cohort model be used to estimate net drifts (overall annual percentage change), local drifts (annual percentage change in each age group), longitudinal age curves (expected longitudinal age-specific rate), and period (cohort) relative risks.

RESULTS

In 2019, the global incidence of migraine increased to 87.6 million (95% UI: 76.6, 98.7), with an increase of 40.1% compared to 1990. India, China, United States of America, and Indonesia had the highest number of incidences, accounting for 43.6% of incidences globally. Females experienced a higher incidence than males, the highest incidence rate was observed in the 10-14 age group. However, there was a gradual transition in the age distribution of incidence from teenagers to middle-aged populations. The net drift of incidence rate ranged from 3.45% (95% CI: 2.38, 4.54) in high-middle Socio-demographic Index (SDI) regions to -4.02% (95% CI: -4.79, -3.18) in low SDI regions, 9 of 204 countries showed increasing trends (net drifts and its 95% CI were > 0) in incidence rate. The age-period-cohort analysis results showed that the relative risk of incidence rate generally showed unfavorable trends over time and in successively birth cohorts among high-, high-middle-, and middle SDI regions, but low-middle- and low-SDI regions keep stable.

CONCLUSIONS

Migraine is still an important contributor to the global burden of neurological disorders worldwide. Temporal trends in migraine incidence are not commensurate with socioeconomic development and vary widely across countries. Both sexes and all age groups should get healthcare to address the growing migraine population, especially adolescents and females.

Multiple Chemical Sensitivity: It's time to catch up to the science

Multiple chemical sensitivity (MCS) is a complex medical condition associated with low dose chemical exposures. MCS is characterized by diverse features and common comorbidities, including fibromyalgia, cough hypersensitivity, asthma, and migraine, and stress/anxiety, with which the syndrome shares numerous neurobiological processes and altered functioning within diverse brain regions. Predictive factors linked to MCS comprise genetic influences, gene-environment interactions, oxidative stress, systemic inflammation, cell dysfunction, and psychosocial influences. The development of MCS may be attributed to the sensitization of transient receptor potential (TRP) receptors, notably TRPV1 and TRPA1. Capsaicin inhalation challenge studies demonstrated that TRPV1 sensitization is manifested in MCS, and functional brain imaging studies revealed that TRPV1 and TRPA1 agonists promote brain-region specific neuronal variations. Unfortunately, MCS has often been inappropriately viewed as stemming exclusively from psychological disturbances, which has fostered patients being stigmatized and ostracized, and often being denied accommodation for their disability. Evidence-based education is essential to provide appropriate support and advocacy. Greater recognition of receptor-mediated biological mechanisms should be incorporated in laws, and regulation of environmental exposures.

Forecasting migraine with machine learning based on mobile phone diary and wearable data

INTRODUCTION

Triggers, premonitory symptoms and physiological changes occur in the preictal migraine phase and may be used in models for forecasting attacks. Machine learning is a promising option for such predictive analytics. The objective of this study was to explore the utility of machine learning to forecast migraine attacks based on preictal headache diary entries and simple physiological measurements.

METHODS

In a prospective development and usability study 18 patients with migraine completed 388 headache diary entries and self-administered app-based biofeedback sessions wirelessly measuring heart rate, peripheral skin temperature and muscle tension. Several standard machine learning architectures were constructed to forecast headache the subsequent day. Models were scored with area under the receiver operating characteristics curve.

RESULTS

Two-hundred-and-ninety-five days were included in the predictive modelling. The top performing model, based on random forest classification, achieved an area under the receiver operating characteristics curve of 0.62 in a hold-out partition of the dataset.

DISCUSSION

In this study we demonstrate the utility of using mobile health apps and wearables combined with machine learning to forecast headache. We argue that high-dimensional modelling may greatly improve forecasting and discuss important considerations for future design of forecasting models using machine learning and mobile health data.

Effect of short-term air pollution exposure on migraine: A protocol for systematic review and meta-analysis on human observational studies

BACKGROUND

The World Health Organization (WHO) has identified air pollution as one of the greatest environmental risks to public health. High levels of ambient air pollution are known to have adverse health effects, but the relationship between exposure to air pollutants and migraine attack has not been established.

OBJECTIVES

This study aims to systematically review the effects of short-term exposure to fine and coarse particulate matter (PM), ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide on migraine attack.

METHODS

The systematic review and meta-analysis will follow the WHO handbook for guideline development. Our protocol will comply with the guidelines of the Preferred Reporting Items for Systematic Review and meta-Analysis Protocols.

ELIGIBILITY CRITERIA

Original peer-reviewed studies conducted in the general population regardless of age and sex to investigate the association between short-term exposure to ambient air pollutants and migraine will be eligible for inclusion. Only time-series, case-crossover, and panel studies will be included.

INFORMATION SOURCES

We will search the electronic databases MEDLINE, Embase, Web of Science, Global Health, Cumulative Index to Nursing and Allied Health Literature in accordance with the pre-established search strategy. We will also check the reference list of included papers and previous reviews for supplementary search.

DATA SYNTHESIS METHOD

We will perform data extraction in accordance with the predesigned table. Using random-effects meta-analysis, we will present summary statistics (RRs and corresponding 95% CIs) associated with standardized increases in each pollutant level. Heterogeneity between studies will be assessed using 80% prediction intervals (PI). Subgroup analyzes will be performed to explore sources of heterogeneity, if any. The main findings will be presented in summary of finding table, visual display and narrative synthesis. We will review the impact of each air pollutant exposure separately.

EVIDENCE APPRAISAL

We will employ the adaption of Grading of Recommendations, Assessment, Development, and Evaluations tool to assess the confidence in the body of evidence.

Investigating the effects of weather on headache occurrence using a smartphone application and artificial intelligence: A retrospective observational cross-sectional study

OBJECTIVE

To investigate the relationship between weather and headache occurrence using big data from an electronic headache diary smartphone application with recent statistical and deep learning (DL)-based methods.

BACKGROUND

The relationship between weather and headache occurrence remains unknown.

METHODS

From a database of 1 million users, data from 4375 users with 336,951 hourly headache events and weather data from December 2020 to November 2021 were analyzed. We developed statistical and DL-based models to predict the number of hourly headache occurrences mainly from weather factors. Temporal validation was performed using data from December 2019 to November 2020. Apart from the user dataset used in this model development, the physician-diagnosed headache prevalence was gathered.

RESULTS

Of the 40,617 respondents, 15,127/40,617 (37.2%) users experienced physician-diagnosed migraine, and 2458/40,617 (6.1%) users had physician-diagnosed non-migraine headaches. The mean (standard deviation) age of the 4375 filtered users was 34 (11.2) years, and 89.2% were female (3902/4375). Lower barometric pressure (p < 0.001, gain = 3.9), higher humidity (p < 0.001, gain = 7.1), more rainfall (p < 0.001, gain = 3.1), a significant decrease in barometric pressure 6 h before (p < 0.001, gain = 11.7), higher barometric pressure at 6:00 a.m. on the day (p < 0.001, gain = 4.6), lower barometric pressure on the next day (p < 0.001, gain = 6.7), and raw time-series barometric type I (remaining low around headache attack, p < 0.001, gain = 10.1) and type II (decreasing around headache attack, p < 0.001, gain = 10.1) changes over 6 days, were significantly associated with headache occurrences in both the statistical and DL-based models. For temporal validation, the root mean squared error (RMSE) was 13.4, and the determination coefficient (R² ) was 52.9% for the statistical model. The RMSE was 10.2, and the R² was 53.7% for the DL-based model.

CONCLUSIONS

Using big data, we found that low barometric pressure, barometric pressure changes, higher humidity, and rainfall were associated with an increased number of headache occurrences.

Measuring pain and nociception: Through the glasses of a computational scientist. Transdisciplinary overview of methods

In a healthy state, pain plays an important role in natural biofeedback loops and helps to detect and prevent potentially harmful stimuli and situations. However, pain can become chronic and as such a pathological condition, losing its informative and adaptive function. Efficient pain treatment remains a largely unmet clinical need. One promising route to improve the characterization of pain, and with that the potential for more effective pain therapies, is the integration of different data modalities through cutting edge computational methods. Using these methods, multiscale, complex, and network models of pain signaling can be created and utilized for the benefit of patients. Such models require collaborative work of experts from different research domains such as medicine, biology, physiology, psychology as well as mathematics and data science. Efficient work of collaborative teams requires developing of a common language and common level of understanding as a prerequisite. One of ways to meet this need is to provide easy to comprehend overviews of certain topics within the pain research domain. Here, we propose such an overview on the topic of pain assessment in humans for computational researchers. Quantifications related to pain are necessary for building computational models. However, as defined by the International Association of the Study of Pain (IASP), pain is a sensory and emotional experience and thus, it cannot be measured and quantified objectively. This results in a need for clear distinctions between nociception, pain and correlates of pain. Therefore, here we review methods to assess pain as a percept and nociception as a biological basis for this percept in humans, with the goal of creating a roadmap of modelling options.

Primary headache disorders in Latin America and the Caribbean: A meta-analysis of population-based studies

BACKGROUND

In this manuscript, we aim to systematically estimate the pooled prevalence and incidence of primary headaches and its subtypes (migraine, tension-type headache, and chronic headaches) in Latin America and the Caribbean, describing its epidemiological profile and associated factors.

METHODS

We systematically searched PubMed/MEDLINE, Scopus, and LILACS (From conception to March 2021), for populational studies reporting the epidemiology of primary headaches and their associated factors in Latin America and the Caribbean. The data extraction was conducted independently. We performed random-effect model meta-analysis of prevalence (overall primary headaches and by subtypes) and associated factors, assessed potential sources of heterogeneity, the risk of bias, publication bias, and the evidence certainty (GRADE methodology).

RESULTS

We included 32 populational studies (38 subpopulations, n = 63,813). The prevalence of primary headaches was 41.4% (95% CI 31.1-52.2%; n = 54,357), 15% for migraine (95% CI 12.0-18.3; n = 53,658 individuals), 20.6% for tension-type headache (95% CI 12.4-30.2; n = 25,840), and 6% for chronic headaches (95% CI 3.3-9.6; n = 21,720), with high between-study heterogeneity. No incidence data was found. Female sex, white ethnicity, high BMI, comorbid mental health disorders, and low-back pain were associated with higher prevalence of primary headaches. The prevalence was less in rural areas.

CONCLUSION

In Latin America and the Caribbean, primary headaches are highly prevalent affecting young females disproportionally. The prevalence of chronic headaches is higher than in other systematic global and regional estimations. The presence of comorbidities as modifiable risk factors should encourage their integration as targets for community-based preventive and therapeutic interventions.

PROTOCOL REGISTRATION NUMBER

CRD42018105116.

Wildfire smoke exposure and emergency department visits for headache: A case-crossover analysis in California, 2006-2020

OBJECTIVE

To evaluate the association of short-term exposure to overall fine particulate matter of <2.5 μm (PM_2.5 ) and wildfire-specific PM_2.5 with emergency department (ED) visits for headache.

BACKGROUND

Studies have reported associations between PM_2.5 exposure and headache risk. As climate change drives longer and more intense wildfire seasons, wildfire PM_2.5 may contribute to more frequent headaches.

METHODS

Our study included adult Californian members (aged ≥18 years) of a large de-identified commercial and Medicare Advantage claims database from 2006 to 2020. We identified ED visits for primary headache disorders (subtypes: tension-type headache, migraine headache, cluster headache, and "other" primary headache). Claims included member age, sex, and residential zip code. We linked daily overall and wildfire-specific PM_2.5 to residential zip code and conducted a time-stratified case-crossover analysis considering 7-day average PM_2.5 concentrations, first for primary headache disorders combined, and then by headache subtype.

RESULTS

Among 9898 unique individuals we identified 13,623 ED encounters for primary headache disorders. Migraine was the most frequently diagnosed headache (N = 5534/13,623 [47.6%]) followed by "other" primary headache (N = 6489/13,623 [40.6%]). For all primary headache ED diagnoses, we observed an association of 7-day average wildfire PM_2.5 (odds ratio [OR] 1.17, 95% confidence interval [CI] 0.95-1.44 per 10 μg/m³ increase) and by subtype we observed increased odds of ED visits associated with 7-day average wildfire PM_2.5 for tension-type headache (OR 1.42, 95% CI 0.91-2.22), "other" primary headache (OR 1.40, 95% CI 0.96-2.05), and cluster headache (OR 1.29, 95% CI 0.71-2.35), although these findings were not statistically significant under traditional null hypothesis testing. Overall PM_2.5 was associated with tension-type headache (OR 1.29, 95% CI 1.03-1.62), but not migraine, cluster, or "other" primary headaches.

CONCLUSIONS

Although imprecise, these results suggest short-term wildfire PM_2.5 exposure may be associated with ED visits for headache. Patients, healthcare providers, and systems may need to respond to increased headache-related healthcare needs in the wake of wildfires and on poor air quality days.

Alcohol as a trigger of migraine attacks in people with migraine. Results from a large prospective cohort study in English-speaking countries

OBJECTIVE

To assess whether alcohol intake is associated with the onset of migraine attacks up to 2 days after consumption in individuals with episodic migraine (EM).

BACKGROUND

Although alcohol has long been suspected to be a common migraine trigger, studies have been inconclusive in proving this association.

METHODS

This was an observational prospective cohort study among individuals with migraine who registered to use a digital health platform for headache. Eligible individuals were aged ≥18 years with EM who consumed alcohol and had tracked their headache symptoms and alcohol intake for ≥90 days. People who did not drink any alcohol were excluded. The association of alcohol intake ("Yes/No") and of the number of alcoholic beverages in the 2 days preceding a migraine attack was assessed accounting for the presence of migraine on day-2 and its interaction with alcohol intake on day-2, and further adjusted for sex, age, and average weekly alcohol intake.

RESULTS

Data on 487 individuals reporting 5913 migraine attacks and a total of 40,165 diary days were included in the analysis. Presence of migraine on day-2 and its interaction with alcohol intake on day-2 were not significant and removed from the model. At the population level, alcohol intake on day-2 was associated with a lower probability of migraine attack (OR [95% CI] = 0.75 [0.68, 0.82]; event rate 1006/4679, 21.5%), while the effect of alcohol intake on day-1 was not significant (OR [95% CI] = 1.01 [0.91, 1.11]; event rate 1163/4679, 24.9%) after adjusting for sex, age, and average weekly alcohol intake. Similar results were obtained with the number of beverages as exposure.

CONCLUSIONS

In this English-speaking cohort of individuals with EM who identified themselves as mostly low-dose alcohol consumers, there was no significant effect on the probability of a migraine attack in the 24 h following consumption, and a slightly lower likelihood of a migraine attack from 24 to 48 h following use.

Prevalence and correlates of sleep quality in the Chinese college students with migraine: a cross-sectional study

Background: Migraineurs are often plagued by sleep disorders. The university student population is high in number and is more vulnerable to migraines. However, no study has analyzed the sleep quality of students with migraine and related contributing factors. Objective: We used the Pittsburgh Sleep Quality Index (PSQI) scale to assess the sleep of migraine patients among college students and to explore the influencing factors of sleep quality. Methods: We performed primary screening for migraine using the ID-migraine screening, and further assessed headache characteristics, sleep, anxiety, depression, and mobile phone addiction in college students with positive primary screening, then diagnosed migraine according to the third edition of the International Classification of Headache Disorders (ICHD-3). Finally, we analyzed the factors influencing sleep quality using Binary Logistic Regression Analysis. Those with scores greater than 5 points on the PSQI scale were believed to have poor sleep quality. Results: The prevalence of migraine was 6.6%. A total of 545 migraineurs were eventually included in the analysis, the incidence of poor sleep quality was 64.04%. The three factors of experiencing aura (OR = 2.966, 95%CI = 1.756-5.010, P < 0.05), anxiety (OR = 2.778, 95%CI = 1.434-5.382, P < 0.05), and high Mobile phone addiction index (MPAI) score (OR = 1.025, 95%CI = 1.002-1.049, P < 0.05) contributed enormously to poor sleep quality. Moreover, the factors of aura symptoms (OR = 3.796, 95%CI = 2.041-7.058, P < 0.05), anxiety (OR = 3.146, 95%CI = 1.473-6.719, P < 0.05), and MPAI score (OR = 1.028, 95%CI = 1.002-1.054, P < 0.05) influenced the sleep quality of female migraineurs rather than male migraineurs. Conclusions: The incidence of poor sleep quality is high among university students with migraine. Aura symptoms, anxiety, and high MPAI score influence the sleep quality of migraineurs, especially females. The proposal of prevention and intervention measures is of great importance to the physical and mental health of students with migraine. Clinical Trial Registration: identifier ChiCTR1800014343.

Ambient NO2 exposure induces migraine in rats: Evidence, mechanisms and interventions

Migraine is a complex neurological disorder with a high disability rate. Although the precipitating factors of migraine remain unclear, previous studies suggest that when there is excess nitrogen dioxide (NO₂) pollution in the atmosphere, the medical demand due to migraine attacks increases sharply. However, the main role of NO₂ as a trigger for migraine is not yet well understood. The purpose of this study was to explore the relationship between NO₂ exposure and the occurrence of migraine as well as the possible underlying mechanisms. We first investigated whether repeated short-term NO₂ exposure could induce behavioural and biological migraine phenotypes in rats. Next, capsazepine (CZP) was used to block transient receptor potential cation channel subfamily V member 1 (TRPV1) in vivo, and CZP and vitamin E (VE) were used to verify the role of reactive oxygen species (ROS)-TRPV1 signalling in NO₂-induced migraine in primary trigeminal neurones in vitro. We demonstrated that short-term repeated NO₂ exposure can significantly induce migraine in rats, and its key molecular mechanism may be related to ROS burst and its downstream TRPV1 channel activation. The findings of this study will enhance the understanding of the neurotoxic mechanism of NO₂, provide new clues for identifying the aetiology of migraine, and lay a new experimental basis for implementing migraine-related preventive and therapeutic control measures.

Urban air pollution and emergency department visits related to central nervous system diseases

Ambient air pollution has been associated with adverse neurological health outcomes. Ambient pollutants are thought to trigger oxidative stress and inflammation to which vulnerable populations, such as elderly may be particularly susceptible. Our study investigated the possible association between concentrations of ambient air pollutants and the number of emergency department (ED) visits for nervous system disorders among people residing in a large Canadian city. A time-stratified case-crossover study design combining data from the National Ambulatory Care Reporting System (NACRS) and the National Air Pollution Surveillance (NAPS) between 2004 and 2015 was used. Two air quality health indices were considered in additional to specific pollutants, including carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃) and fine particulate matter (PM_2.5). Weather condition data were included in the models. ED visits with a discharge diagnosis were identified using ICD-10 codes (G00-G99). The analysis was stratified by sex and age, also by seasons. The associations were investigated in arrays organized as 18 strata and 15 time lags (in days) for each pollutant. Overall, 140,511 ED visits were included for the analysis. Most ED visits were related to episodic and paroxysmal diagnoses (G40-G47, 64%), with a majority of visits for migraines (G43, 39%). Among females, an increase of 0.1ppm ambient CO was associated with an increased risk of paroxysmal diagnoses at day 1 (RR = 1.019 (95%CI 1.004–1.033)), day 6 (1.024 (1.010–1.039)) and day 7 (1.022 (1.007–1.036). PM_2.5 and SO₂, and air quality indices were similarly associated with ED visits for episodic and paroxysmal disorders in days 6 and 7. Findings highlight that ambient air pollution is associated with an increased number of ED visits for nervous system disorders, particularly visits for paroxysmal diagnoses.

Skin wetness sensitivity across body sites commonly affected by pain in people with migraine

Objective

The objective of this study was to evaluate skin wetness perception and thermal sensitivity in people with migraine and similar healthy controls.

Background

Environmental triggers, such as cold and humidity, are known triggers for pain in people with migraine. Sensory inputs might be implicated in such heightened responses to cold‐humid environments, such that a migraine‐induced hypersensitivity to cold wetness could be present in people with migraine. However, we lack empirical evidence on skin thermal and wetness sensitivity across skin sites commonly associated with reported pain in migraine, such as the forehead.

Methods

This prospective cross‐sectional observational study, conducted in a university hospital setting, evaluated skin wetness perceptions and thermal sensations to wet non‐noxious warm‐wet, neutral‐wet, and cold‐wet stimuli applied to the forehead, the posterior neck, and the index finger pad of 12 patients with migraine (mean and standard deviation for age 44.5 ± 13.2 years, 7/12 [58%] women) and 36 healthy controls (mean and standard deviation for age 39.4 ± 14.6 years, 18/36 [50%] women).

Results

On the forehead, people with migraine reported a significantly higher wetness perception than healthy controls across all thermal stimulus (15.1 mm, 95% confidence interval [CI]: 1.8 to 28.5, p = 0.027, corresponding to ~ 15% difference), whereas no significant differences were found on the posterior neck nor on the index finger pad. We found no differences among groups in overall thermal sensations (−8.3 mm, 95% CI: −24.0 to 7.3, p = 0.291; −7.8 mm, 95% CI: −25.3 to 9.7, p = 0.375; and 12.4 mm, 95% CI: −4.0 to 28.9, p = 0.133; forehead, posterior neck, and index finger, respectively).

Conclusion

These findings indicate that people with migraine have a heightened sensitivity to skin wetness on the forehead area only, which is where pain attacks occur. Future studies should further explore the underlying mechanisms (e.g., TRPM8‐mediated cold‐wet allodynia) that lead to greater perception of wetness in people with migraine to better understand the role of environmental triggers in migraine.

Managing of Migraine in the Workplaces: Knowledge, Attitudes and Practices of Italian Occupational Physicians

Background and Objectives: Migraine is a debilitating disorder, whose incidence peak in the age group of 30-39 years overlaps with the peak of employment years, potentially representing a significant issue for occupational physicians (OP). The present study was performed in order to characterize their knowledge, attitudes and practices on migraine in the workplaces. Materials and Methods: A convenience sample of 242 Italian OP (mean age 47.8 ± 8.8 years, males 67.4%) participated in an internet-based survey by completing a structured questionnaire. Results: Adequate general knowledge of migraine was found in the majority of participants. Migraine was identified as a common and severe disorder by the majority of respondents (54.0% and 60.0%). Overall, 61.2% of participants acknowledged migraine as difficult to manage in the workplace, a status that made it more likely for OP understanding its potential frequency (Odds Ratio [OR] 3.672, 95% confidence interval [95%CI] 1.526-8.831), or reported previous managing of complicated cases requiring conditional fitness to work judgement (OR 4.761, 95%CI 1.781-2.726). Moreover, professionals with a qualification in occupational medicine (OR 20.326, 95%CI 2.642-156.358), acknowledging the difficult managing of migraine in the workplaces (OR 2.715, 95%CI 1.034-7.128) and having received any request of medical surveillance for migraine (OR 22.878, 95%CI 4.816-108.683), were more likely to recommend specific requirements for migraineur workers. Conclusions: Migraine was recognized as a common disorder, but also as a challenging clinical problem for OP. Participating OP exhibited a substantial understanding of migraine and its triggers, but residual false beliefs and common misunderstanding may impair the proper management of this disorder, requiring improved and specifically targeted interventions.

Effectiveness and Safety of Memantine for Headache: A Meta-analysis of Randomized Controlled Studies

OBJECTIVE

The effectiveness and safety of memantine for headache are elusive, and this meta-analysis aimed to explore the influence of memantine versus placebo for headache.

METHODS

We have searched PubMed, Embase, Web of science, EBSCO, and Cochrane library databases through May 2021 and included randomized controlled trials reporting memantine versus placebo for headache patients. This meta-analysis is performed using the random-effects model.

RESULTS

Our meta-analysis included 4 randomized controlled trials and 229 patients. Compared with control group for headache, memantine treatment could substantially reduce headache days (mean difference [MD] = -3.10; 95% confidence interval [CI] = -5.46 to -0.75; P = 0.01), pain intensity (MD, -0.43; 95% CI, -0.85 to -0.01; P = 0.04), monthly attack frequency (MD, -2.14; 95% CI, -2.83 to -1.46; P < 0.00001), and Migraine Disability Assessment Test (MD, -5.63; 95% CI, -6.46 to -4.79; P < 0.00001) but revealed no significant influence on days for acute pain medications, adverse events, or nausea/vomiting.

CONCLUSIONS

Memantine treatment is effective and safe to treat headache.

Global, regional, and national burden of migraine in 204 countries and territories, 1990 to 2019

ABSTRACT

Data from the Global Burden of Disease Study 2019 were used to report the burden of migraine in 204 countries and territories during the period 1990 to 2019, through a systematic analysis of point prevalence, annual incidence, and years lived with disability (YLD). In 2019, the global age-standardised point prevalence and annual incidence rate of migraine were 14,107.3 (95% Uncertainty Interval [UI] 12,270.3-16,239) and 1142.5 (95% UI 995.9-1289.4) per 100,000, an increase of 1.7% (95% UI 0.7%-2.8%) and 2.1% (95% UI 1.1%-2.8%) since 1990, respectively. Moreover, the global age-standardised YLD rate in 2019 was 525.5 (95% UI 78.8-1194), an increase of 1.5% (95% UI -4.4% to 3.3%) since 1990. The global point prevalence of migraine in 2019 was higher in females and increased by age up to the 40 to 44 age group, then decreased with increased age. Belgium (22,400.6 [95% UI: 19,305.2-26,215.8]), Italy (20,337.7 [95% UI: 17,724.7-23,405.8]), and Germany (19,436.4 [95% UI: 16,806.2-22,810.3]) had the 3 highest age-standardised point prevalence rates for migraine in 2019. In conclusion, there were large intercountry differences in the burden of migraine, and this burden increased significantly across the measurement period. These findings suggest that migraine care needs to be included within the health system to increase population awareness regarding the probable risk factors and treatment strategies especially among young adults and middle-aged women, as well as to increase the data on migraines.

Is the Exposome Involved in Brain Disorders through the Serotoninergic System?

Serotonin (5-hydroxytryptamine, 5-HT) is a biogenic monoamine acting as a neurotransmitter in the central nervous system (CNS), local mediator in the gut, and vasoactive agent in the blood. It has been linked to a variety of CNS functions and is implicated in many CNS and psychiatric disorders. The high comorbidity between some neuropathies can be partially understood by the fact that these diseases share a common etiology involving the serotoninergic system. In addition to its well-known functions, serotonin has been shown to be a mitogenic factor for a wide range of normal and tumor cells, including glioma cells, in vitro. The developing CNS of fetus and newborn is particularly susceptible to the deleterious effects of neurotoxic substances in our environment, and perinatal exposure could result in the later development of diseases, a hypothesis known as the developmental origin of health and disease. Some of these substances affect the serotoninergic system and could therefore be the source of a silent pandemic of neurodevelopmental toxicity. This review presents the available data that are contributing to the appreciation of the effects of the exposome on the serotoninergic system and their potential link with brain pathologies (neurodevelopmental, neurodegenerative, neurobehavioral disorders, and glioblastoma).

Physical inactivity and headache disorders: Cross-sectional analysis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND

Physical inactivity has been linked to headache disorders but estimates based on the current World Health Organization physical activity guidelines are unknown.

OBJECTIVE

To test the associations between headache disorders and physical inactivity in the ELSA-Brasil cohort.

METHODS

In a cross-sectional analysis, linear (continuous variables) and logistic regression models (categorical variables) tested the associations of physical activity levels in the leisure time, commuting time, and combined leisure time physical activity + commuting time physical activity domains with headache disorders, adjusted for the effects of sociodemographic data, cardiovascular risk variables, psychiatric disorders, and migraine prophylaxis medication.

RESULTS

Of 15,105 participants, 14,847 (54.4% women) provided data on physical activity levels and headache. Higher physical activity levels (continuous values) in the leisure time physical activity domain associated with lower migraine and tension-type headache occurrence and lower headache attack frequency, while in the commuting time physical activity domain it associated with more frequent headache attacks. Compared to people who met World Health Organization physical activity levels in the leisure time physical activity or combining leisure time physical activity + commuting time physical activity domains (i.e. ≥150 min.wk^-1 of moderate and/or ≥75 min.wk^-1 of vigorous physical activity), physical inactivity associated with higher migraine occurrence, while somewhat active (i.e. not meeting World Health Organization recommendations) associated with higher migraine and tension-type headache occurrence. Physical inactivity in the commuting time physical activity domain associated with higher tension-type headache in men and lower migraine in women. Physical inactivity within vigorous leisure time physical activity intensity, but not moderate leisure time physical activity, associated with higher migraine, mostly in women. Finally, physical inactivity associated with higher headache attack frequency regardless headache subtype.

CONCLUSION

Physical inactivity and unmet World Health Organization physical activity levels associate with primary headaches, with heterogeneous associations regarding headache subtype, sex, physical activity domain/intensity, and headache frequency in the ELSA-Brasil study.

The efficacy of ginger for the treatment of migraine: A meta-analysis of randomized controlled studies

INTRODUCTION

The efficacy of ginger for migraine remains controversial. We conduct a systematic review and meta-analysis to explore the influence of ginger versus placebo on treatment in migraine patients.

METHODS

We have searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through September 2020 for randomized controlled trials (RCTs) assessing the effect of ginger versus placebo on treatment efficacy in migraine patients. This meta-analysis is performed using the random-effect model.

RESULTS

Three RCTs are included in the meta-analysis. Overall, compared with control group in migraine patients, ginger treatment is associated with substantially improved pain free at 2 h (RR = 1.79; 95% CI = 1.04-3.09; P = 0.04) and reduced pain scores at 2 h (MD = -1.27; 95% CI = -1.46 to -1.07; P < 0.00001), but reveals no obvious impact on treatment response (RR = 2.04; 95% CI = 0.35-11.94; P = 0.43) or total adverse events (RR = 0.80; 95% CI = 0.46-1.41; P = 0.44). The incidence of nausea and vomiting is obviously lower in ginger group than that in control group.

CONCLUSIONS

Ginger is safe and effective in treating migraine patients with pain outcomes assessed at 2 h.

The effect of weather variables on the severity, duration, and frequency of headache attacks in the cases of episodic migraine and episodic tension-type headache

Background/aim

Although many headache patients report that the frequency and severity of attacks vary according to the season or weather in clinical practice, the relationship between the characteristics of the attacks and the weather is not very clear in episodic headaches. We aimed to compare the effects of weather variables (temperature, wind speed, wind direction, humidity, pressure, ultraviolet index, and sunshine duration) on episodic migraine (EM) and episodic tension-type headache (ETTH) attacks (incidence, duration, and severity).

Materials and methods

Fifty patients with EM and fifty patients with ETTH diagnosed according to International Classification of Headache Disorders-II are included in the study. Patients were given one diary for headache follow-up. The evaluation form on the relationship between the duration, frequency, and severity of the pain and the findings obtained from the headache diaries were compared with the daily weather data, and the two headache groups were compared with each other in terms of the effect of meteorological data on the pain characteristics.

Results

It is determined that mean wind velocity in EM attacks is significantly higher when compared to the tension-type headache (TTH) attacks and mean UV index is significantly higher in TTH attacks (p = 0.018 and 0.039). Mean UV index in TTH attack days was reported higher in women than men (p = 0.044). Mean sunshine duration in TTH attack days was reported longer in women than men (p = 0.050). When mean age gets higher in patients with migraine, mean temperature in the days of attack gets lower (r = –0.146 and p = 0.046).

Conclusion

During the treatment of migraine and TTH patients, recommendations and warnings about weather conditions can be made. This information can guide patients to regulate their daily living activities. The importance of considering the weather-headache relationship during the review of the current treatment in cases of unresponsiveness to treatment should be kept in mind.

The Efficacy of Memantine for the Treatment of Migraine: A Meta-Analysis of Randomized Controlled Studies

INTRODUCTION

The efficacy of memantine for migraine remains controversial. We conduct a systematic review and meta-analysis to explore the influence of memantine versus placebo on treatment in migraine patients.

METHODS

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through February 2020 for randomized controlled trials assessing the effect of memantine versus placebo on treatment efficacy in migraine patients. This meta-analysis is performed using the random-effect model.

RESULTS

Three randomized controlled trials are included in the meta-analysis. Overall, compared with control group in migraine patients, memantine treatment is associated with substantially reduced monthly attack frequency (mean difference [MD], -2.14; 95% confidence interval [CI], -2.83 to -1.46; P < 0.00001), number of migraine days (MD, -4.17; 95% CI, -6.40 to -1.93; P = 0.0003) and Migraine Disability Assessment (MD, -5.63; 95% CI, -6.46 to -4.79; P < 0.00001), but demonstrates no obvious influence on acute pain medications (MD, -1.23; 95% CI, -4.63 to 2.17; P = 0.48).

CONCLUSIONS

Memantine treatment may benefit to the control of migraine.

Particulate Matter 10 (PM10) Is Associated with Epistaxis in Children and Adults

The impact of atmospheric concentration of particulate matter ≤10 μm in diameter (PM₁₀) continues to attract research attention. This study aimed to evaluate the effects of meteorological factors, including PM₁₀ concentration, on epistaxis presentation in children and adults. We reviewed the data from 1557 days and 2273 cases of epistaxis between January 2015 and December 2019. Eligible patients were stratified by age into the children (age ≤17 years) and adult groups. The main outcome was the incidence and cumulative number of epistaxis presentations in hospital per day and month. Meteorological factors and PM₁₀ concentration data were obtained from the Korea Meteorological Administration. Several meteorological factors were associated with epistaxis presentation in hospital; however, these associations differed between children and adults. Only PM₁₀ concentration was consistently associated with daily epistaxis presentation in hospital among both children and adults. Additionally, PM₁₀ concentration was associated with the daily cumulative number of epistaxis presentations in hospital in children and adults. Furthermore, the monthly mean PM₁₀ concentration was significantly associated with the total number of epistaxis presentations in the corresponding month. PM₁₀ concentration should be regarded as an important environmental factor that may affect epistaxis in both children and adults.

Noninvasive vagus nerve stimulation and morphine transiently inhibit trigeminal pain signaling in a chronic headache model

Noninvasive vagus nerve stimulation suppressed persistent trigeminal nociception in a chronic headache model similarly to morphine and may provide a safe, nonaddictive abortive therapy for chronic headache.

Introduction:

Chronic headache conditions are characterized by persistent sensitization of the trigeminal system, which involves dysfunction of descending pain modulation. We previously reported that noninvasive vagus nerve stimulation (nVNS) inhibits trigeminal nociception in models of episodic migraine through a mechanism involving enhanced serotonergic and GABAergic descending pain signaling.

Objectives:

The analgesic effectiveness of nVNS and morphine were investigated in an animal model of chronic headache mediated by the combination of the 3 migraine risk factors of neck muscle tension, paradoxical sleep deprivation, and pungent odors.

Methods:

Sprague–Dawley rats were injected with complete Freund's adjuvant in the trapezius and sleep deprived for 1 night to promote trigeminal sensitization. After 7 days, animals were exposed to a pungent odor, and mechanical nocifensive head withdrawal responses were determined using von Frey filaments. Beginning on day 3 after odor exposure, animals were treated daily with either nVNS or morphine for 7 days.

Results:

Exposure of animals sensitized by neck inflammation and sleep deprivation to a pungent odor resulted in a prolonged state of trigeminal nociception. Daily administration of nVNS or morphine significantly repressed the nocifensive response; however, cessation resulted in a return to heightened pretreatment nocifensive levels.

Conclusions:

The combination of reported migraine risk factors promotes a state of sustained trigeminal hypersensitivity characteristic of chronic headache. Daily nVNS was similarly effective as morphine in inhibiting nociception and may represent a safer, opioid-sparing therapeutic option for other chronic pain disorders involving sensitization of the trigeminal system by promoting descending pain modulation.

Associations of daily weather and ambient air pollution with objectively assessed sleep duration and fragmentation: a prospective cohort study

OBJECTIVE

Given the lack of studies examining the associations between daily weather and air pollution with nightly objective sleep over multiple weeks, we quantified these associations in a prospective cohort of healthy participants with episodic migraine.

METHODS

Ninety-eight participants completed daily electronic diaries and wore an actigraph for an average of 45 ds, and a total 4406 nights of data were collected. Nightly sleep characteristics including duration, wake after sleep onset (WASO), and efficiency were assessed using wrist actigraphy. Daily weather parameters and air pollution levels were collected from local weather station and ground-level air quality monitors. We used linear fixed effects models adjusting for participant, day of the week, and day of the year (for weather analysis), and additionally adjusted for temperature and relative humidity (for air pollution analysis).

RESULTS

The participants were 35 ± 12 yrs old and 86 were women. A 10 °F higher daily average temperature was associated with 0.88 (95% CI: 0.06, 1.70) minutes longer WASO and 0.14% (95% CI: -0.01%, 0.30%) lower sleep efficiency on that night. A 14 parts per billion (ppb) (interquartile range) higher daily maximum eight-h ozone was associated with 7.51 (95% CI: 3.23, 11.79) minutes longer sleep duration on that night. Associations did not differ between cold (October-March) and warm (April-September) seasons.

CONCLUSIONS

Higher daily ozone was associated with longer sleep duration and modest associations were observed between higher temperature and lower WASO and lower efficiency.

Ambient Air Pollution Increases the Risk of Cerebrovascular and Neuropsychiatric Disorders through Induction of Inflammation and Oxidative Stress

Exposure to ambient air pollution is a well-established determinant of health and disease. The Lancet Commission on pollution and health concludes that air pollution is the leading environmental cause of global disease and premature death. Indeed, there is a growing body of evidence that links air pollution not only to adverse cardiorespiratory effects but also to increased risk of cerebrovascular and neuropsychiatric disorders. Despite being a relatively new area of investigation, overall, there is mounting recent evidence showing that exposure to multiple air pollutants, in particular to fine particles, may affect the central nervous system (CNS) and brain health, thereby contributing to increased risk of stroke, dementia, Parkinson's disease, cognitive dysfunction, neurodevelopmental disorders, depression and other related conditions. The underlying molecular mechanisms of susceptibility and disease remain largely elusive. However, emerging evidence suggests inflammation and oxidative stress to be crucial factors in the pathogenesis of air pollution-induced disorders, driven by the enhanced production of proinflammatory mediators and reactive oxygen species in response to exposure to various air pollutants. From a public health perspective, mitigation measures are urgent to reduce the burden of disease and premature mortality from ambient air pollution.

Ambient fine particulate matter and hospital admissions for ischemic and hemorrhagic strokes and transient ischemic attack in 248 Chinese cities

Few studies have investigated the acute effects of fine particulate matter (PM_2.5) on the risk of stroke subtypes and transient ischemic attack (TIA) in low- and middle-income countries. The primary aim of this study was to assess the associations between short-term exposure to PM_2.5 and daily hospital admissions for total cerebrovascular disease, ischemic and hemorrhagic strokes, and TIA in China. A total of 8,359,162 hospital admissions in 248 Chinese cities from 2013 to 2017 were identified from the Hospital Quality Monitoring System of China. Generalized additive models with quasi-Poisson regression were used to estimate the associations in each city, and random-effect meta-analyses were conducted to combine the city-specific estimates. We found that a 10 μg/m³ increase in PM_2.5 concentration was significantly associated with a 0.19% (95% CI, 0.13% to 0.25%), 0.26% (95% CI, 0.17% to 0.35%), and 0.26% (95% CI, 0.13% to 0.38%) increase in same-day hospital admissions for total cerebrovascular disease, ischemic stroke, and TIA, respectively. In contrast, a non-significant negative association with PM_2.5 was observed for hemorrhagic stroke in the main analyses (lag 0 day), which became statistically significant when using other single-day exposures (lag 1 or 2 days) or moving average exposures (lag 0-1, 0-2, or 0-3 days) as exposure metric. These associations were robust to adjustment for other criteria air pollutants in two-pollutant models. For ischemic stroke, the effect estimates were significantly larger in people aged 65-74 years, in cool season, and in cities with lower annual average PM_2.5 concentrations. The exposure-response curves were nonlinear with a leveling off at high concentrations. These results contribute to the relatively limited literature on the PM_2.5-related risks of cerebrovascular events in low- and middle-income countries.

"Dr. Google, I am in Pain"-Global Internet Searches Associated with Pain: A Retrospective Analysis of Google Trends Data

We aimed to rank the most common locations of pain among Google users globally and locally and analyze secular and seasonal trends in pain-related searches in the years 2004-2019. We used data generated by Google Trends (GT) to identify and analyze global interest in topics (n = 24) related to locations of pain and how these progressed over time. We analyzed secular trends and time series decomposition to identify seasonal variations. We also calculated the interest in all topics with reference to the relative search volume (RSV) of "Abdominal pain". Google users were most commonly interested in "Headache" (1.30 [times more frequently than "Abdominal pain"]), "Abdominal pain" (1.00), and "Back pain" (0.84). "Headache" was the most frequent search term in n = 41 countries, while "Abdominal pain" was the most frequent term in n = 27 countries. The interest in all pain-related topics except "Dyspareunia" increased over time. The sharpest increase was observed for "Abdominal pain" (5.67 RSV/year), and "Toothache" (5.52 RSV/year). Most of the topics revealed seasonal variations. Among pain-related topics, "Headache," "Abdominal pain," and "Back pain" interested most Google users. GT is a novel tool that allows retrospective investigation of complaints among Internet users.

Prevalence and risk factors associated with headache amongst medical staff in South China

BACKGROUND

A previous study by our team reported the prevalence of primary headache disorders and factors associated with headache among nurses in three hospitals in North China. The aim of this cross-sectional survey was to learn more about how medical nurses in South China were affected by headache. Additionally, we determined the prevalence of headache and measured the impact of headache among doctors in mainland China for the first time.

METHODS

Stratified random cluster sampling was used to select 280 physicians and 365 nurses from various departments in four hospitals in Sanya, which is one of southernmost cities in China. Information was collected on demographic data, occupational factors and headache characteristics by using a structured questionnaire.

RESULTS

Among 645 medical staff, 548 (85%) responded (doctors = 240, nurses = 308). Among the medical staff, the 1-year prevalence of primary headache disorders was 50%, with 25.9% experiencing migraine and 24.1% experiencing tension-type headache (TTH). The prevalence of migraine in female doctors was higher than that in female nurses, although this difference was not significant (32.4% vs. 29.8%, P = 0.628). Multivariate analysis showed that being female and working in other specialties (Emergency Department & Radiology Department) remained independent risk factors for migraine in doctors (OR 2.314 and 3.223). In nurses, being married was a risk factor for migraine (OR 3.728), and job titles remained an independent risk factor for migraine and TTH (OR 2.294 and 4.695). Working more than 6 night-shifts per month was associated with an increased prevalence of migraine and TTH in doctors; the same was true in nurses for migraine, but not for TTH.

CONCLUSION

The prevalence of primary headache disorders in both nurses and doctors is higher than that in the general population in South China. Our study shows that occupation, geography and sex may play an important role. Further, female doctors are more susceptible than female nurses to migraine. The risk factors relevant to headache that were found in this study should provide an important reference for promoting occupational health in medical staff, especially female doctors in China.