Patients with migraine are right about their perception of temperature as a trigger: time series analysis of headache diary data

Climate temperature and seasonal influences on the prevalence of temporomandibular disorders in South Korea

This study aimed to explore seasonal variations in temporomandibular disorder (TMD) prevalence in South Korea, utilizing nationwide population-based big data. Data corresponding to the Korean Standard Classification of Diseases code of K07.6, which identifies TMD, were extracted from the Health Insurance Review and Assessment Service online platform for the period from 2010 to 2022. Additionally, we integrated these data with climate temperature records from the Korean Meteorological Administration. We subsequently conducted a statistical analysis of TMD patient data on a monthly and seasonal basis over the past 13 years to assess prevalence. Over the past 13 years, the number of TMD patients in Korea has steadily increased. The prevalence of TMD rose from 0.48% (224,708 out of a total population of 50,515,666) in 2010 to 0.94% (482,241 out of a total population of 51,439,038) in 2022, marking a 1.96-fold increase. Among children under 10 years of age, no significant differences were observed in TMD prevalence between boys and girls. However, a distinct female predominance emerged after the age of 10, with an average female-to-male ratio of 1.51:1. The peak prevalence of TMD occurred in individuals in their 20 s, followed by adolescents in their late 10 s. The majority of TMD patients were concentrated in Seoul and Gyeonggi province, with metropolitan areas accounting for 50% of the total patient count. Seasonally, TMD patient numbers showed no significant increase in winter compared with spring or summer. The temperature difference, defined as the absolute difference between the highest and lowest temperatures for each month, showed a positive correlation with TMD patient counts. A greater temperature difference was associated with higher patient counts. The strongest correlation between temperature differences and TMD patient numbers was observed in winter (r = 0.480, p < 0.01), followed by summer (r = 0.443, p < 0.01), and spring (r = 0.366, p < 0.05). Temperature differences demonstrated a significantly stronger correlation with the increase in the number of TMD patients than absolute climate temperatures. This aspect should be a key consideration when examining seasonal trends in TMD prevalence in South Korea.

Subjective Physical Symptoms Related to Bad Weather Among Persons Undergoing Medical Check-Up: A Single-Center Observational Study

Background and aim The prevalence and characteristics of physical complaints related to bad weather among the general population remain poorly understood. This study aimed to elucidate the characteristics of subjective physical symptoms related to bad weather. Methods A cross-sectional survey was conducted by using self-reported health-related questionnaires obtained from individuals undergoing annual medical check-ups at a municipal hospital in Japan. Participants were asked about the presence and details of physical symptoms related to bad weather, together with other health-related questions. Results Among the 133 participants, 42 (32%) (95%CI 24-40) reported experiencing physical conditions related to bad weather. Among these 42 patients, the most common ailment was headache (67%; n=28), followed by low back pain (21%; n=9), fatigue (19%; n=8), and stiff neck/shoulder discomfort (12%; n=5). Comparison between individuals with and without bad weather-related conditions revealed that those affected were younger (p=0.0014) and exhibited higher numerical rating scale scores for gastrointestinal problems (p=0.0027), irritability/agitation (p<0.0001), and sleep disorders (p=0.0295). These associations were confirmed even after adjusting for age and sex. Conclusions Physical conditions related to bad weather, represented by headache, fatigue, and back pain, can be seen in 25-40% of the general population, especially in younger age groups. Individuals with these conditions are more likely to experience irritability/agitation, gastrointestinal problems, and sleep disorders.

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.

Cold-Stimulus Headache in Children and Adolescents

The literature on cold-stimulus headache (CSH) is relatively sparse compared to other primary headache disorders and the studies on the pediatric population are very limited. This systematic review aims to analyze the evidence on CSH in children and adolescents focusing on epidemiology, clinical features, pathogenic mechanisms, and treatments. Our review included 25 studies, among which 9 papers include pediatric cases (4 pediatric samples, 5 mixed samples of children and adults). The aim of this work is to highlight the features of CSH in children and adolescents. In children, the prevalence of CSH is higher than in adults and it is not gender-specific. There is a relevant family history for CSH and the comorbidity with migraine is significant. The triggers and clinical features of CSH due to ingesting a cold stimulus in children overlap with those in adults. CSH due to external application of a cold stimulus (or to environmentally low temperatures) is not studied in children and adolescents. We describe in detail a new pediatric case of CSH triggered by low ambient temperatures; to the best of our knowledge, this represents the first description in the literature. In conclusion, CSH in children is probably underestimated and has peculiar features compared to adults; further studies are needed to better understand its clinical features and pathophysiology.

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.

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.

To tolerate weather and to tolerate pain: two sides of the same coin? The Tromsø Study 7

ABSTRACT

It is a common belief that weather affects pain. Therefore, we hypothesized that weather can affect pain tolerance. This study used data from over 18,000 subjects aged 40 years or older from the general population, who participated in the Tromsø Study 7. They underwent a one-time assessment of cuff algometry pressure pain tolerance (PPT) and cold pain tolerance (CPT), tested with a cold pressor test. The results showed a clear seasonal variation in CPT. The rate of withdrawal in the cold pressor test was up to 75% higher in months in the warmer parts of the year compared with January 2016. There was no seasonal variation in PPT. The study not only found a nonrandom short-term variation in PPT but also indications of such a variation in CPT. The intrinsic timescale of this short-term variation in PPT was 5.1 days (95% % confidence interval 4.0-7.2), which is similar to the observed timescales of meteorological variables. Pressure pain tolerance and CPT correlated with meteorological variables, and these correlations changed over time. Finally, temperature and barometric pressure predicted future values of PPT. These findings suggest that weather has a causal and dynamic effect on pain tolerance, which supports the common belief that weather affects pain.

The chronobiology of migraine: a systematic review

BACKGROUND

The paroxysmal nature of migraine is a hallmark of the disease. Some patients report increased attack frequency at certain seasons or towards the end of the week, while others experience diurnal variations of migraine attack onset. This systematic review investigates the chronobiology of migraine and its relation to the periodicity of attacks in existing literature to further understand the oscillating nature of migraine.

MAIN BODY

PubMed and Embase were systematically searched and screened for eligible articles with outcome measures relating to a circadian, weekly or seasonal distribution of migraine attacks. We found that the majority of studies reported morning hours (6 am-12 pm) as the peak time of onset for migraine attacks. More studies reported Saturday as weekly peak day of attack. There was no clear seasonal variation of migraine due to methodological differences (primarily related to location), however four out of five studies conducted in Norway reported the same yearly peak time indicating a possible seasonal periodicity phenomenon of migraine.

CONCLUSIONS

The findings of the current review suggest a possible role of chronobiologic rhythms to the periodicity of migraine attacks. Future studies are, however, still needed to provide more knowledge of the oscillating nature of migraine.

Multivariate analysis of the impact of weather and air pollution on emergency department visits for night-time headaches among children: retrospective, clinical observational study

OBJECTIVES

To examine the association between the number of visits to the emergency department (ED) by children for night-time headaches and exposure to multifaceted factors, such as meteorological conditions and air pollution.

DESIGN

We conducted a clinical observational time-series analysis study.

SETTING

We reviewed consecutive patients younger than 16 years of age at the primary ED centre in Kobe city, Japan, during the night shift (19:30-7:00 hours) between 1 January 2011 and 31 December 2019.

PARTICIPANTS

In total, 265 191 children visited the ED; 822 presented with headache during the study period.

PRIMARY OUTCOME MEASURES

We investigated the effects of meteorological factors and air pollutants by multivariate analysis of Poisson regression estimates. A subanalysis included the relationship between the number of patients with night-time headaches and the above factors by sex. Furthermore, the effect of typhoon landing on patient visits for headache was also analysed. Headache was not classified because examinations were performed by general paediatricians (non-specialists).

RESULTS

The number of patients with night-time headaches displayed distinct seasonal changes, with peaks during the summer. Multivariate analysis of Poisson regression estimates revealed a significant positive relationship between the number of patients for headache and mean temperature. Subanalysis by sex indicated a positive relationship between the number of patients with headache and mean temperature in both sexes; however, it was significant only for females. No relationship was found between the number of patients with headache and air pollution. There was no change in the number of patients for night-time headaches 3 days before and after typhoon landing.

CONCLUSIONS

High temperature is the main factor for visiting ED for night-time headaches among children in Kobe city. Our results suggest that preventive measures against night-time headaches may be possible by reducing time spent outside during summer.

Affective temperaments and lifetime major depression in female migraine patients

The relationship between affective temperaments and migraine is not well studied to date. It is also uncertain whether some affective temperaments may predispose the migraine patients to major depression (MD). We hypothesized that migraine patients had more affective temperament traits than HCs, and certain affective temperament traits in migraine patients are associated with lifetime MD. The sample included fifty-eight female migraine patients and age-matched 55 healthy women. The migraine was diagnosed according to the third edition of International Classification of Headache Disorders (ICHD-III). Lifetime MD was determined by means of Structured Clinical Interview I for DSM-IV. Migraine Disability Assessment (MIDAS) Questionnaire was applied to participants to determine the impact of migraine on daily life. Affective temperamental traits were assessed through Temperament Evaluation of Memphis, Pisa, Paris and San Diego Auto-questionnaire. All affective temperament traits (p < .0001) and the rate of MD (p = .002) were significantly higher in migraine patients compared to HCs. Non-depressive migraine patients (n = 36) had significantly more hyperthymic temperament traits compared to depressive patients (n = 22) (p = .04). Specifically, depressive temperament traits were significantly associated with higher lifetime MD in female migraine patients (B = 0.196, Exp(B) = 1.216, p = .01). Our findings suggest that affective temperaments may predispose some women to migraine, and depressive temperament may have a casual role in the development of lifetime depression in migraine patients.

Affective Temperaments and Meteoropathy Among Women: A Cross-sectional Study

The main goal of the study was to assess the relationship between affective temperaments and meteoropathy among women and examine meteorosensitivity as a mediator in this relationship. The issue of affective temperaments and meteoropathy has not been considered in the literature. The sample consisted of 450 Caucasian women gathered via the online recruitment platform. The participants’ ages ranged from 18 to 70 years (M = 30.01; SD = 9.10). The Polish version of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire was used to assess affective temperaments (depressive, cyclothymic, hyperthymic, irritable and anxious). Meteorosensitivity and meteoropathy were assessed using the Polish adaptation of the METEO-Q questionnaire. A large positive correlation was found between meteorosensitivity and meteoropathy. Medium positive correlations were found between meteorosensitivity/meteoropathy and cyclothymic and anxious temperaments. Small positive correlations were revealed between depressive and irritable temperaments and both meteorosensitivity and meteoropathy scales. No correlation was found between hyperthymic temperament and meteorosensitivity/meteoropathy. Mediation analyses indicated cyclothymic and anxious temperaments affected meteoropathy both directly and indirectly through meteorosensitivity as a mediator. The most severe meteoropathy symptoms in the studied sample were asthenia, an indefinite feeling of malaise and irritability. The results suggest affective temperaments may be related to meteoropathy symptoms in women.

Comprehensive Migraine Initiative in the Pediatric Emergency Department Improves Treatment Outcomes

OBJECTIVE

To compare pediatric migraine treatment efficacy in the emergency department before and after the implementation of a comprehensive migraine initiative, consisting of a standardized treatment protocol, provider educational series and standardized physician documentation template.

BACKGROUND

Pediatric migraine is common, accounting for 1% of pediatric emergency department visits. Yet there is large variability in treatment practices, with few studies looking into measures of both clinical effectiveness and timeliness of treatment following implementation of standardized protocols.

METHODS

A single-center retrospective chart review of pediatric patients presenting to the emergency department with migraine before and after implementation of an institutional headache initiative designed to more effectively and efficiently deliver care to pediatric migraine patients.

RESULTS

The study yielded 110 patients each in the intervention and preintervention groups. There were no significant differences in patient characteristics with respect to age, gender, or initial pain score. Compared with the preintervention group, the intervention group demonstrated a significant reduction in headache pain score prior to discharge (decrease of 5.9 vs 4.8 in preintervention group, P value .006) with a greater percentage of patients achieving ≥50% reduction in pain (82% vs 67% in preintervention group, P value .039). Additionally, we found a significantly decreased time to treatment in the intervention group compared with the preintervention group (1.8 vs 2.1 hours, P value .046).

CONCLUSION

Through the use of a standardized treatment protocol, improved provider education, and ease of documentation, this comprehensive migraine initiative improved efficacy and efficiency of migraine treatment in the pediatric emergency department.

The relationship between exposure to hot/cold weather and the clinical features of headaches in patients with migraine and tension-type headaches

Background and purpose: This study investigates the relationship between exposure to hot/cold weather and the characteristic clinical features of headaches in patients with migraine and tension-type headaches.Methods: This cross-sectional study was conducted with the participation of 190 patients with migraine, and 140 patients with tension-type headaches. The patients were evaluated using a form that collected data on their sociodemographic profile, the clinical features of their headaches, any accompanying symptoms and their relationships with changes in the weather (hot/cold). The headaches of all the participants in the study were thought to be triggered by exposure to hot/cold weather.Results: In the patients with migraine, the exposure to hot/cold weather as a trigger was not found to have a significant relationship with age, body mass index or the characteristic clinical features of headaches (p > 0.05). In patients with tension-type headaches, exposure to hot/cold weather as a trigger was found to have a significant relationship with body mass index (p = 0.019), but not with age or the characteristic clinical features of headaches (p > 0.05).Conclusions: In obese patients with tension-type headache, it was found that hot weather triggered headache more than cold weather. In patients with migraine and tension-type headaches, no relationship was found between exposure to hot/cold weather as a trigger and the clinical features of headaches. The accurate identification of the factors precipitating headaches by both clinicians and patients can help lower the frequency of headaches.

"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.

Decomposed Temporal Complexity Analysis of Neural Oscillations and Machine Learning Applied to Alzheimer's Disease Diagnosis

Despite growing evidence of aberrant neuronal complexity in Alzheimer's disease (AD), it remains unclear how this variation arises. Neural oscillations reportedly comprise different functions depending on their own properties. Therefore, in this study, we investigated details of the complexity of neural oscillations by decomposing the oscillations into frequency, amplitude, and phase for AD patients. We applied resting-state magnetoencephalography (MEG) to 17 AD patients and 21 healthy control subjects. We first decomposed the source time series of the MEG signal into five intrinsic mode functions using ensemble empirical mode decomposition. We then analyzed the temporal complexities of these time series using multiscale entropy. Results demonstrated that AD patients had lower complexity on short time scales and higher complexity on long time scales in the alpha band in temporal regions of the brain. We evaluated the alpha band complexity further by decomposing it into amplitude and phase using Hilbert spectral analysis. Consequently, we found lower amplitude complexity and higher phase complexity in AD patients. Correlation analyses between spectral complexity and decomposed complexities revealed scale-dependency. Specifically, amplitude complexity was positively correlated with spectral complexity on short time scales, whereas phase complexity was positively correlated with spectral complexity on long time scales. Regarding the relevance of cognitive function to the complexity measures, the phase complexity on the long time scale was found to be correlated significantly with the Mini-Mental State Examination score. Additionally, we examined the diagnostic utility of the complexity characteristics using machine learning (ML) methods. We prepared a feature pool using multiple sparse autoencoders (SAEs), chose some discriminating features, and applied them to a support vector machine (SVM). Compared to the simple SVM and the SVM after feature selection (FS + SVM), the SVM with multiple SAEs (SAE + FS + SVM) had improved diagnostic accuracy. Through this study, we 1) advanced the understanding of neuronal complexity in AD patients using decomposed temporal complexity analysis and 2) demonstrated the effectiveness of combining ML methods with information about signal complexity for the diagnosis of AD.

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

OBJECTIVE

Migraine is a common recurrent headache disorder affecting 14% American adults. Although weather and air pollution are often reported by patients with migraine as precipitating factors, previous studies have had mixed results.

METHODS

We prospectively collected migraine headache onset data using electronic questionnaires from 98 adults with episodic migraine in the Greater Boston area (2016-2017). Each participant was followed for an average of 45 days for a total of 4406 days of observation. Temperature, relative humidity, and barometric pressure data were obtained from local weather station. Daily average fine particulate matter, daily maximum 1-hour sulfur dioxide, daily maximum 1-hour nitrogen dioxide, daily maximum 8-hour ozone, and daily maximum 8-hour carbon monoxide from local air pollution monitors. We conducted a repeated measures analysis using fixed effects logistic regression models. In the models we adjusted for day of week, a natural cubic spline term of day of the year with 4 degrees of freedom, and a participant identifier. We additionally adjusted for linear terms of temperature and relative humidity in the air pollution analyses. We also applied logistic regression models with generalized estimating equation (GEE) and autoregressive correlation structure in the sensitivity analysis.

RESULTS

The mean age was 35 years and 88% were women. Mean temperature was 56.9 °F, relative humidity 67.3%, and fine particulate matter 7.3 μg/m³. Higher relative humidity was associated with higher odds of migraine headache, but the association was only observed in warm season (April-September). Higher levels of daily maximum 8-hour ozone and daily maximum 8-hour carbon monoxide appeared to be associated with higher odds of migraine headache onset in cold season (October-March). Although the associations for ozone and relative humidity were attenuated and no longer statistically significant in the overall GEE analysis, the differing associations by season remained.

CONCLUSIONS

We found that higher relative humidity was associated with higher odds of migraine headache onset in warm season, and traffic-related gaseous pollutants may be associated with higher odds of migraine headache onset in cold season.

Emerging Perspectives on Pain Management by Modulation of TRP Channels and ANO1

Receptor-type ion channels are critical for detection of noxious stimuli in primary sensory neurons. Transient receptor potential (TRP) channels mediate pain sensations and promote a variety of neuronal signals that elicit secondary neural functions (such as calcitonin gene-related peptide [CGRP] secretion), which are important for physiological functions throughout the body. In this review, we focus on the involvement of TRP channels in sensing acute pain, inflammatory pain, headache, migraine, pain due to fungal infections, and osteo-inflammation. Furthermore, action potentials mediated via interactions between TRP channels and the chloride channel, anoctamin 1 (ANO1), can also generate strong pain sensations in primary sensory neurons. Thus, we also discuss mechanisms that enhance neuronal excitation and are dependent on ANO1, and consider modulation of pain sensation from the perspective of both cation and anion dynamics.

Influence of Climate on the Incidence of RCVS - A Retrospective Study From Taiwan

BACKGROUND

Cold weather is reportedly a precipitator of reversible cerebral vasoconstriction syndrome (RCVS) in a few cases. We systematically investigated whether meteorological factors correlate with the occurrence of RCVS.

METHODS

We conducted a retrospective analysis of a cohort of patients diagnosed with RCVS or probable RCVS, based on International Classification of Headache Disorders, third edition (ICHD-3) criteria, in a hospital-based headache center from March 2005 to February 2014. Monthly averages of local weather data measured in Taipei were obtained from the Central Weather Bureau in Taiwan. Primary weather variables were compared with the number of monthly new-onset cases of RCVS.

RESULTS

We recruited 226 patients with established RCVS and 72 patients with probable RCVS during a 108-month study period. Incidence of RCVS was higher in winter than summer months (3.3 persons/month [SD: 2.0] vs 2.1 persons/month [SD: 1.5], P = .013). The monthly incidence of RCVS correlated negatively with mean daily temperature (r = -0.231, P = .016) and average precipitation (r = -0.269, P = .005), but positively with barometric pressure (r = 0.274, P = .004). These 3 correlated meteorological factors together explained about 10% of the variance in RCVS monthly incidence (R²  = 0.095, P = .015).

CONCLUSION

RCVS was found to be more common in winter months and to be associated with weather variables in Taiwan. Further studies are needed to explore the underlying mechanisms of these associations.

Weather and Health Symptoms

Weather affects the daily lives of individuals. However, its health effects have not been fully elucidated. It may lead to physical symptoms and/or influence mental health. Thus, we evaluated the association between weather parameters and various ailments. We used daily reports on health symptoms from 4548 individuals followed for one month in October of 2013, randomly sampled from the entirety of Japan. Weather variables from the monitoring station located closest to the participants were used as weather exposure. Logistic mixed effects model with a random intercept for each individual was applied to evaluate the effect of temperature and humidity on physical symptoms. Stratified analyses were conducted to compare weather effects by sex and age group. The lag day effects were also assessed. Joint pain was associated with higher temperature (1.87%, 95% CI = 1.15 to 2.59) and humidity (1.38%, 95% CI = 0.78 to 2.00). Headaches was increased by 0.56% (95% CI = −0.55 to 1.77) per 1 °C increase in the maximum temperature and by 1.35% per 1 °C increase in dew point. Weather was associated with various physical symptoms. Women seem to be more sensitive to weather conditions in association with physical symptoms, especially higher humidity and lower temperature.

Analysis of Trigger Factors in Episodic Migraineurs Using a Smartphone Headache Diary Applications

Background

Various stimuli can trigger migraines in susceptible individuals. We examined migraine trigger factors by using a smartphone headache diary application.

Method

Episodic migraineurs who agreed to participate in our study downloaded smartphone headache diary application, which was designed to capture the details regarding headache trigger factors and characteristics for 3 months. The participants were asked to access the smartphone headache diary application daily and to confirm the presence of a headache and input the types of trigger factors.

Results

Sixty-two participants kept diary entries until the end of the study. The diary data for 4,579 days were analyzed. In this data set, 1,099 headache days (336 migraines, 763 non-migraine headaches) were recorded; of these, 772 headache events had with trigger factors, and 327 events did not have trigger factors. The common trigger factors that were present on headache days included stress, fatigue, sleep deprivation, hormonal changes, and weather changes. The likelihood of a headache trigger was 57.7% for stress, 55.1% for sleep deprivation, 48.5% for fatigue, and 46.5% for any trigger. The headaches with trigger factors were associated with greater pain intensity (p<0.001), headache-related disability (p<0.001), abortive medication use (p = 0.02), and the proportion of migraine (p < 0.001), relative to those without trigger factors. Traveling (odd ratios [OR]: 6.4), hormonal changes (OR: 3.5), noise (OR: 2.8), alcohol (OR: 2.5), overeating (OR: 2.4), and stress (OR:1.8) were significantly associated with migraines compared to non-migraine headaches. The headaches that were associated with hormonal changes or noise were more often migraines, regardless of the preventive medication. The headaches due to stress, overeating, alcohol, and traveling were more often migraines without preventive medication, but it was not evident with preventive medication.

Conclusion

Smartphone headache diary application is an effective tool to assess migraine trigger factors. The headaches with trigger factors had greater severity or migraine features. The type of triggers and the presence of preventive medication influenced the headache characteristics; hence, an investigation of trigger factors would be helpful in understanding migraine occurrences.