Vascular biomarkers in migraine

Poor healthy lifestyle and life's essential 8 are associated with higher risk of new-onset migraine: a prospective cohort study

BACKGROUND

Lifestyle are closely related to migraine. However, there is a lack of studies investigating the association between Healthy lifestyle or Life's Essential 8 (LE8) and the risk of migraine. The objective of this research was to investigate the relationship between Healthy lifestyle scores and Life's essential 8 scores, and migraine.

METHODS

332,895 UK Biobank participants without migraine were included. Healthy lifestyle were assessed using seven lifestyle factors, and categorized as poor, intermediate, or ideal. LE8, based on the American Heart Association (AHA) Guidelines for Cardiovascular Health (CVH), consist of eight indicators classified as low, moderate, or high CVH. The Cox proportional hazard model was employed to examine the association between Healthy lifestyle scores, LE8 scores, and migraine, with calculations for population-attributable fraction (PAF) and cumulative incidence.

RESULTS

During a median follow-up of 13.58 years, participants in intermediate (HR: 0.91; 95% CI: 0.85, 0.99) or ideal category of Healthy lifestyle (HR: 0.81; 95% CI: 0.73, 0.91) significantly reduced migraine risk compared to the poor category. Similarly, high CVH (HR: 0.73; 95% CI: 0.58, 0.92) also lowered migraine risk, while moderate CVH (HR: 0.93; 95% CI: 0.85, 1.02) did not show a difference compared to low CVH. If all individuals adhered to higher categories of Healthy lifestyle and LE8, approximately 11.38% and 22.05% of migraine cases could be prevented. Among individual lifestyle factors, maintaining an ideal body mass index (BMI), physical activity, sleep duration, sleep pattern, and sedentary time were associated with substantial reductions in migraine risk, by 5.65%, 0.81%, 10.16%, 16.39%, and 6.57%, respectively.

CONCLUSION

Our study provides evidence that poor Healthy lifestyle and Life's Essential 8 are associated with higher risk of new-onset migraine.

Prophylactic treatment can modify vascular risk biomarkers in high-frequency episodic and chronic migraine patients: a pilot study

To evaluate whether preventive treatment can modify endothelial and oxidative biomarkers of vascular disease risk in patients with high-frequency episodic and chronic migraine. In this observational, prospective pilot study, 88 prophylactic treatment-naïve patients with episodic and chronic migraine and 56 healthy sex/age matched controls underwent ultrasonography exams and blood tests at baseline, and again in the migraine patients after 3 months' treatment with metoprolol or topiramate. Biomarkers for endothelial function and oxidative stress were analyzed. At baseline, patients with migraine in the low-frequency episodic group had differences exclusively in nitrates 17.6 versus 27.33 µM; p = 0.046 compared to the controls. However, when comparing the group comprised of patients with high-frequency episodic migraine and chronic migraine versus controls, statistically significant differences appeared in hsCRP 2.68 versus 1.64 mg/dL; p = 0.049, vWF antigen (133% vs. 110%; p = 0.020, vWF activity (111% vs. 90%; p = 0.010) and isoprostane levels (181 vs. 238 µM; p = 0.05). Only in the chronic migraine subgroup did we found statistically significant differences in CIMT (0.60 vs. 0.54 mm; p = 0.042) which were significantly greater than in the controls. After treatment, patients who respond to preventive treatment exhibited significantly higher levels of nitrates (24.2-13.8 µM; p = 0.022) and nitrites (10.4-3.43 µM; p = 0.002) compared than non-responders. Moreover, biomarker levels improved in treatment-responsive patients with migraine; hsCRP levels decreased from 2.54 to 1.69 mg/dL (p < 0.05), vWF activity levels decreased from 124 to 103 IU/dL (p = 0.003) and prothrombin activity decreased from 1.01 to 0.93 (p = 0.01). These differences were also observed in the high-frequency and chronic migraine subgroup and reach statistical significance in the case of hsCRP, which decreased from 2.12 to 0.83 mg/dL (p = 0.048). Patients with migraines have differences in biomarker levels compared to controls, suggesting endothelial and oxidative dysfunction. The greatest differences in biomarker levels compared to controls are observed in migraine patients in the high-frequency and chronic migraine subgroups. Based on our results, preventive treatment is capable of modifying markers of endothelial dysfunction and oxidative stress in migraine patients, even in cases of chronic and high-frequency migraine.

Serological Biomarkers of Chronic Migraine

PURPOSE OF REVIEW

Chronic migraine (CM) is a chronic form of migraine that differs from episodic migraine (EM) in terms of prevalence, comorbidities, response to treatment, and biomarkers. The aim of this review was to summarize the recent findings on serological biomarkers of CM.

RECENT FINDINGS

Neuronal, inflammatory, and vascular markers have been investigated to assess their diagnostic and prognostic ability and treatment effectiveness. Several markers showed significant alterations according to disease status and treatment response in CM. Calcitonin gene-related peptide (CGRP), glutamate, and adiponectin appear to be the most promising blood biomarkers for CM. Most studies have shown altered ictal and interictal levels of these markers in CM compared with those in EM and controls. Additionally, they showed a significant association with treatment outcomes. Total adiponectin and high-molecular-weight adiponectin levels were less studied as biomarkers of CM than CGRP and glutamate levels but showed promising results. The development of suitable biomarkers could revolutionize the diagnosis and treatment of CM and ultimately decrease the disability and societal costs of the disease.

Preventive and Therapeutic Effects of Low-Intensity Ultrasound Stimulation on Migraine in Rats

This study sought to systematically evaluate the prophylactic and therapeutic effects of low-intensity transcranial ultrasound stimulation on migraine in rats. We used video recordings to assess the head scratching behavior and laser speckle contrast imaging to record the changes in cerebral blood flow velocity of freely moving rats in a healthy group, migraine group, migraine group with ultrasound prevention, and migraine group with ultrasound therapy. Results demonstrated that (1) head scratching during migraine attacks in rats was accompanied by an decrease in cerebral blood flow; (2) both ultrasound prevention and therapy significantly reduced the number of head scratches but did not reduce the cerebral blood flow velocity; and (3) the number of head scratches in the ultrasound stimulation groups was not affected by the auditory effect. These results reveal that low-intensity ultrasound has the potential to be used clinically in the prevention and therapeutic treatment of migraine.

Recent Advances in Inflammatory Diagnosis with Graphene Quantum Dots Enhanced SERS Detection

Inflammatory diseases are some of the most common diseases in different parts of the world. So far, most attention has been paid to the role of environmental factors in the inflammatory process. The diagnosis of inflammatory changes is an important goal for the timely diagnosis and treatment of various metastatic, autoimmune, and infectious diseases. Graphene quantum dots (GQDs) can be used for the diagnosis of inflammation due to their excellent properties, such as high biocompatibility, low toxicity, high stability, and specific surface area. Additionally, surface-enhanced Raman spectroscopy (SERS) allows the very sensitive structural detection of analytes at low concentrations by amplifying electromagnetic fields generated by the excitation of localized surface plasmons. In recent years, the use of graphene quantum dots amplified by SERS has increased for the diagnosis of inflammation. The known advantages of graphene quantum dots SERS include non-destructive analysis methods, sensitivity and specificity, and the generation of narrow spectral bands characteristic of the molecular components present, which have led to their increased application. In this article, we review recent advances in the diagnosis of inflammation using graphene quantum dots and their improved detection of SERS. In this review study, the graphene quantum dots synthesis method, bioactivation method, inflammatory biomarkers, plasma synthesis of GQDs and SERS GQD are investigated. Finally, the detection mechanisms of SERS and the detection of inflammation are presented.

Inflammation and endothelial dysfunction in pediatric migraine patients

BACKGROUND

Inflammation and endothelial dysfunction are the suggested underlying mechanisms in migraine. Pentraxins, C-reactive protein, erythrocyte sedimentation rate, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio are good indicators of inflammation. Alterations in insulin levels and insulin sensitivity may trigger endothelial dysfunction. This study evaluates the association between migraine and serum biomarkers of inflammation and endothelial dysfunction in children.

METHODS

Children with migraine and healthy subjects were recruited. Serum samples were obtained in an attack-free period. We collected data on serum levels of complete blood cell count, C-reactive protein, erythrocyte sedimentation rate, pentraxin-3, and data from biochemical investigations. We compared these with clinical data such as age, sex, disease duration, attack frequency, attack duration, analgesic use, family history, and Pediatric Migraine Disability Assessment Questionnaire scores.

RESULTS

We assessed samples from 32 children (11 boys, 21 girls) with migraine and 19 healthy controls (8 boys, 11 girls). We found significantly higher pentraxin-3, insulin, and insulin resistance in patients with migraine (P = 0.001, P = 0.032, and P = 0.008, respectively). A positive directional correlation is found between pentraxin-3 and Pediatric Migraine Disability Assessment Questionnaire scores. The best cut-off values for pentraxin-3 is determined between 12.75 pg/mL to 15 pg/mL in migraineurs.

CONCLUSIONS

In conclusion increased pentraxin-3 levels support the suggestions that inflammation plays a role in pediatric migraine. The vascular endothelial dysfunction is observed by a rise in insulin and insulin resistance levels. Our findings support the idea that ongoing inflammation and vascular endothelial dysfunction between attacks may play a role in migraine pathogenesis in children.

A replication study separates polymorphisms behind migraine with and without depression

The largest migraine genome-wide association study identified 38 candidate loci. In this study we assessed whether these results replicate on a gene level in our European cohort and whether effects are altered by lifetime depression. We tested SNPs of the loci and their vicinity with or without interaction with depression in regression models. Advanced analysis methods such as Bayesian relevance analysis and a neural network based classifier were used to confirm findings. Main effects were found for rs2455107 of PRDM16 (OR = 1.304, p = 0.007) and five intergenic polymorphisms in 1p31.1 region: two of them showed risk effect (OR = 1.277, p = 0.003 for both rs11209657 and rs6686879), while the other three variants were protective factors (OR = 0.4956, p = 0.006 for both rs12090642 and rs72948266; OR = 0.4756, p = 0.005 for rs77864828). Additionally, 26 polymorphisms within ADGRL2, 2 in REST, 1 in HPSE2 and 33 mostly intergenic SNPs from 1p31.1 showed interaction effects. Among clumped results representing these significant regions, only rs11163394 of ADGRL2 showed a protective effect (OR = 0.607, p = 0.002), all other variants were risk factors (rs1043215 of REST with the strongest effect: OR = 6.596, p = 0.003). Bayesian relevance analysis confirmed the relevance of intergenic rs6660757 and rs12128399 (p31.1), rs1043215 (REST), rs1889974 (HPSE2) and rs11163394 (ADGRL2) from depression interaction results, and the moderate relevance of rs77864828 and rs2455107 of PRDM16 from main effect analysis. Both main and interaction effect SNPs could enhance predictive power with the neural network based classifier. In summary, we replicated p31.1, PRDM16, REST, HPSE2 and ADGRL2 genes with classic genetic and advanced analysis methods. While the p31.1 region and PRDM16 are worthy of further investigations in migraine in general, REST, HPSE2 and ADGRL2 may be prime candidates behind migraine pathophysiology in patients with comorbid depression.

Phenotypic and Genotypic Associations Between Migraine and Lipoprotein Subfractions

BACKGROUND AND OBJECTIVE

To evaluate phenotypic and genetic relationships between migraine and lipoprotein subfractions.

METHODS

We evaluated phenotypic associations between migraine and 19 lipoprotein subfraction measures in the Women's Genome Health Study (n = 22,788). We then investigated genetic relationships between these traits using summary statistics from the International Headache Genetics Consortium for migraine (n_case = 54,552, n_control = 297,970) and combined summary data for lipoprotein subfractions (n up to 47,713).

RESULTS

There was a significant phenotypic association (odds ratio 1.27 [95% confidence interval 1.12-1.44]) and a significant genetic correlation at 0.18 (p = 0.001) between migraine and triglyceride-rich lipoproteins (TRLPs) concentration but not for low-density lipoprotein or high-density lipoprotein subfractions. Mendelian randomization (MR) estimates were largely null, implying that pleiotropy rather than causality underlies the genetic correlation between migraine and lipoprotein subfractions. Pleiotropy was further supported in cross-trait meta-analysis, revealing significant shared signals at 4 loci (chr2p21 harboring THADA, chr5q13.3 harboring HMGCR, chr6q22.31 harboring HEY2, and chr7q11.23 harboring MLXIPL) between migraine and lipoprotein subfractions. Three of these loci were replicated for migraine (p < 0.05) in a smaller sample from the UK Biobank. The shared signal at chr5q13.3 colocalized with expression of HMGCR, ANKDD1B, and COL4A3BP in multiple tissues.

CONCLUSIONS

The study supports the association between certain lipoprotein subfractions, especially for TRLP, and migraine in populations of European ancestry. The corresponding shared genetic components may help identify potential targets for future migraine therapeutics.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that migraine is significantly associated with some lipoprotein subfractions.

Metabolic profile changes in serum of migraine patients detected using 1H-NMR spectroscopy

Background

Migraine is a common brain disorder but reliable diagnostic biomarkers in blood are still lacking. Our aim was to identify, using proton nuclear magnetic resonance (¹H-NMR) spectroscopy, metabolites in serum that are associated with lifetime and active migraine by comparing metabolic profiles of patients and controls.

Methods

Fasting serum samples from 313 migraine patients and 1512 controls from the Erasmus Rucphen Family (ERF) study were available for ¹H-NMR spectroscopy. Data was analysed using elastic net regression analysis.

Results

A total of 100 signals representing 49 different metabolites were detected in 289 cases (of which 150 active migraine patients) and 1360 controls. We were able to identify profiles consisting of 6 metabolites predictive for lifetime migraine status and 22 metabolites predictive for active migraine status. We estimated with subsequent regression models that after correction for age, sex, BMI and smoking, the association with the metabolite profile in active migraine remained. Several of the metabolites in this profile are involved in lipid, glucose and amino acid metabolism.

Conclusion

This study indicates that metabolic profiles, based on serum concentrations of several metabolites, including lipids, amino acids and metabolites of glucose metabolism, can distinguish active migraine patients from controls.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-021-01357-w.

Evaluation and treatment of headache associated with moyamoya disease - a narrative review

BACKGROUND

Headache in patients with moyamoya disease is an under-addressed topic in the medical literature. Delay in the diagnosis of moyamoya disease or inappropriate treatment of headache could lead to devastating cerebrovascular outcome. With the evolving understanding of moyamoya disease, migraine pathophysiology, and various migraine-specific medications that have become available, it is crucial to provide an updated overview on this topic.

METHODS

We searched PubMed for keywords including moyamoya disease, moyamoya syndrome, headache in moyamoya, surgical revascularization, surgical bypass, migraine and moyamoya, and calcitonin gene-related peptide (CGRP). We summarized the literature and provide a comprehensive review of the headache presentation, possible mechanisms, the impact of various surgical revascularizations on headache in patients with moyamoya disease, and the medical management of headache incorporating novel migraine-specific treatments.Results and conclusion: The most common headache phenotype is migraine; tension-type headache, hemiplegic migraine, and cluster headache have also been reported. Most patients experience improvement of headache after surgical revascularization, though some patients report worsening, or new-onset headache after surgery. Given the complexity of moyamoya disease, careful consideration of different types of medical therapy for headache is necessary to improve the quality of life while not increasing the risk of adverse cerebrovascular events. More prospective studies are warranted to better understand and manage headache in patients with moyamoya disease.

A critical review of the neurovascular nature of migraine and the main mechanisms of action of prophylactic antimigraine medications

INTRODUCTION

Migraine involves neurovascular, functional, and anatomical alterations. Migraineurs experience an intense unilateral and pulsatile headache frequently accompanied with vomiting, nausea, photophobia, etc. Although there is no ideal preventive medication, frequency in migraine days may be partially decreased by some prophylactics, including antihypertensives, antidepressants, antiepileptics, and CGRPergic inhibitors. However, the mechanisms of action involved in antimigraine prophylaxis remain elusive.

AREAS COVERED

This review recaps some of the main neurovascular phenomena related to migraine and currently available preventive medications. Moreover, it discusses the major mechanisms of action of the recommended prophylactic medications.

EXPERT OPINION

In the last three years, migraine prophylaxis has evolved from nonspecific to specific antimigraine treatments. Overall, nonspecific treatments  mainly involve neural actions, whereas specific pharmacotherapy (represented by CGRP receptor antagonists and CGRPergic monoclonal antibodies) is predominantly mediated by neurovascular mechanisms that may include, among others: (i) reduction in the cortical spreading depression (CSD)-associated events; (ii) inhibition of pain sensitization; (iii) blockade of neurogenic inflammation; and/or (iv) increase in cranial vascular tone. Accordingly, the novel antimigraine prophylaxis promises to be more effective, devoid of significant adverse effects (unlike nonspecific treatments), and more beneficial for the quality of life of migraineurs.

The role of a potential biomarker in patients with migraine: review and new insights

Introduction: The search for an ideal biomarker for migraine has persisted for a long time. There is plentiful evidence of potential biomarkers for migraine found in cerebrospinal fluid, blood, and saliva.Areas covered: Herein, the authors highlight and discuss the most promising candidates in the literature. An electronic search was performed for studies published between 2010 and 2020 in MEDLINE, PubMed, and EMBASE, related to potential biomarkers in migraine patients, found in cerebrospinal fluid, saliva, and serum, focusing on biomarkers that can be related to treatment and clinical outcomes.Expert opinion: An ideal biomarker, or a panel of biomarkers, could revolutionize the way we address and propose treatments for this disease. Once severe presentations and phenotypes have been identified using a reliable biomarker, patients could be treated at earlier disease stages with more specific medications. The most important biomarkers with the most significant levels of evidence comprised calcitonin gene-related peptide (CGRP), glutamate, nerve growth factor, some inflammatory (CRP, TNF-α, interleukins) and oxidative stress markers. CGRP was associated with episodic, chronic migraine and response to treatment. Pituitary adenylate cyclase-activating polypeptide is an emerging neuropeptide involved in migraine diagnostics and severity. New genetic and epigenetic biomarkers will be candidates for future research.

Association Between Hemostatic Profile and Migraine: A Mendelian Randomization Analysis

OBJECTIVE

To assess support for a causal relationship between hemostatic measures and migraine susceptibility using genetic instrumental analysis.

METHODS

Two-sample Mendelian randomization instrumental analyses leveraging available genome-wide association study (GWAS) summary statistics were applied to hemostatic measures as potentially causal for migraine and its subtypes, migraine with aura (MA) and migraine without aura (MO). Twelve blood-based measures of hemostasis were examined, including plasma level or activity of 8 hemostatic factors and 2 fibrinopeptides together with 2 hemostasis clinical tests.

RESULTS

There were significant instrumental effects between increased coagulation factor VIII activity (FVIII; odds ratio [95% confidence interval] 1.05 [1.03, 1.08]/SD, p = 6.08 × 10^-05), von Willebrand factor level (vWF; 1.05 [1.03, 1.08]/SD, p = 2.25 × 10^-06), and phosphorylated fibrinopeptide A level (1.13 [1.07, 1.19]/SD, p = 5.44 × 10^-06) with migraine susceptibility. When extended to migraine subtypes, FVIII, vWF, and phosphorylated fibrinopeptide A showed slightly stronger effects with MA than overall migraine. Fibrinogen level was inversely linked with MA (0.76 [0.64, 0.91]/SD, p = 2.32 × 10^-03) but not overall migraine. None of the hemostatic factors was linked with MO. In sensitivity analysis, effects for fibrinogen and phosphorylated fibrinopeptide A were robust, whereas independent effects of FVIII and vWF could not be distinguished, and FVIII associations were potentially affected by pleiotropy at the ABO locus. Causal effects from migraine to the hemostatic measures were not supported in reverse Mendelian randomization. However, MA was not included due to lack of instruments.

CONCLUSIONS

The findings support potential causality of increased FVIII, vWF, and phosphorylated fibrinopeptide A and decreased fibrinogen in migraine susceptibility, especially for MA, potentially revealing etiologic relationships between hemostasis and migraine.

Giving Researchers a Headache - Sex and Gender Differences in Migraine

Migraine is a common neurovascular disorder affecting ~15% of the general population. Ranking second in the list of years lived with disability (YLD), people living with migraine are greatly impacted by this especially burdensome primary headache disorder. In ~30% of individuals with migraine, transient neurological symptoms occur (migraine aura) that further increase migraine burden. However, migraine burden is differential with respect to sex. Though one-year prevalences in childhood are similar, starting with puberty, migraine incidence increases at a much higher rate in females than males. Thus, migraine over the life course occurs in women three to four times more often than in men. Attacks are also more severe in women, leading to greater disability and a longer recovery period. The sex disparity in migraine is believed to be partly mediated through fluctuations in ovarian steroid hormones, especially estrogen and progesterone, although the exact mechanisms are not yet completely understood. The release of the neuropeptide calcitonin gene-related peptide (CGRP), followed by activation of the trigeminovascular system, is thought to play a key role in the migraine pathophysiology. Given the burden of migraine and its disproportionate distribution, the underlying cause(s) for the observed differences between sexes in the incidence, frequency, and intensity of migraine attacks must be better understood. Relevant biological as well as behavioral differences must be taken into account. To evaluate the scope of the existing knowledge on the issue of biological sex as well as gender differences in migraine, we conducted a systematized review of the currently available research. The review seeks to harmonize existing knowledge on the topic across the domains of biological/preclinical, clinical, and population-level research, which are traditionally synthesized and interpreted in isolation. Ultimately, we identify knowledge gaps and set priorities for further interdisciplinary and informed research on sex and gender differences as well as gender-specific therapies in migraine.

Migraine and risk of stroke

Migraine and stroke are two common and heterogeneous neurovascular disorders responsible for a significant burden for those affected and a great economic cost for the society. There is growing evidence that migraine increases the overall risk of cerebrovascular diseases. In this review, based on available literature through a PubMed search, we found that ischaemic stroke in people with migraine is strongly associated with migraine with aura, young age, female sex, use of oral contraceptives and smoking habits. The risk of transient ischaemic attack also seems to be increased in people with migraine, although this issue has not been extensively investigated. Although migraine appears to be associated with haemorrhagic stroke, the migraine aura status has a small influence on this relationship. Neuroimaging studies have revealed a higher prevalence of asymptomatic structural brain lesions in people with migraine. They are also more likely to have unfavourable vascular risk factors; however, the increased risk of stroke seems to be more apparent among people with migraine without traditional risk factors. The mechanism behind the migraine-stroke association is unknown. In light of the higher risk of stroke in people with migraine with aura, it is important to identify and modify any vascular risk factor. There is currently no direct evidence to support that a migraine prophylactic treatment can reduce future stroke in people with migraine.

MRI evaluation of the relationship between carotid artery endothelial shear stress and brain white matter lesions in migraine

Although white matter lesions are frequently detected in migraine patients, underlying mechanisms remain unclear. Low carotid artery endothelial shear stress has been associated with white matter lesions. We aimed to investigate the association between carotid artery endothelial shear stress and white matter lesions in migraine. In 40 elderly migraine patients (n = 29 females, 75 years [SD 3]) and 219 controls (n = 80 females, 74 years [SD 3]) from the PROSPER-MRI study, carotid artery endothelial shear stress was estimated on 1.5 T gradient-echo phase contrast MRI. White matter lesion volumes were calculated from structural MRI scans. Analyses were adjusted for age, sex, cardiovascular risk factors and cardiovascular disease. Migraine patients had lower mean endothelial shear stress compared to controls (0.90 [SD 0.15] vs. 0.98 [SD 0.16] Pa; P = 0.03). The association between mean endothelial shear stress and white matter lesion volume was greater for the migraine group than control group (P for interaction = 0.05). Within the migraine group, white matter lesion volume increased with decreasing endothelial shear stress (β-0.421; P = 0.01). In conclusion, migraine patients had lower endothelial shear stress which was associated with higher white matter lesion volume.

Pentraxin 3 (PTX3): A Molecular Marker of Endothelial Dysfunction in Chronic Migraine

Even though endothelial dysfunction is known to play a role in migraine pathophysiology, studies regarding levels of endothelial biomarkers in migraine have controversial results. Our aim was to evaluate the role of pentraxin 3 (PTX3) and soluble tumour necrosis factor-like weak inducer of apoptosis (sTWEAK) as potential biomarkers of endothelial dysfunction in chronic migraine (CM). We performed a case-control study including 102 CM patients and 28 control subjects and measured serum levels of markers of endothelial dysfunction (PTX3 and sTWEAK) and inflammation [high-sensitivity C-reactive protein (hs-CRP)] as well as brachial artery flow-mediated dilation (FMD) during interictal periods. Interictal serum levels of PTX3 and sTWEAK were higher in CM patients than in controls (1350.6 ± 54.8 versus 476.1 ± 49.4 pg/mL, p < 0.001 and 255.7 ± 21.1 versus 26.4 ± 2.6 pg/mL, p < 0.0001; respectively). FMD was diminished in CM patients compared to controls (9.6 ± 0.6 versus 15.2 ± 0.9%, p < 0.001). Both PTX3 and sTWEAK were negatively correlated with FMD (r = −0.508, p < 0.001 and r = −0.188, p = 0.033; respectively). After adjustment of confounders, PTX3 remained significantly correlated to FMD (r = −0.250, p = 0.013). Diagnosis of CM was 68.4 times more likely in an individual with levels of PTX3 ≥ 832.5 pg/mL, suggesting that PTX3 could be a novel biomarker of endothelial dysfunction in CM.

Migraine, headache, and mortality in women: a cohort study

BACKGROUND

Migraine carries a high global burden, disproportionately affects women, and has been implicated as a risk factor for cardiovascular disease. Migraine with aura has been consistently associated with increased risk of cardiovascular mortality. However, published evidence on relationships between migraine or non-migraine headache and all-cause mortality is inconclusive. Therefore, we aimed to estimate the effect of non-migraine headache and migraine as well as migraine subtypes on all-cause and cause-specific mortality in women.

METHODS

In total, 27,844 Women's Health Study participants, aged 45 years or older at baseline, were followed up for a median of 22.7 years. We included participants who provided information on migraine (past history, migraine without aura, or migraine with aura) or headache status and a blood sample at study start. An endpoints committee of physicians evaluated reports of incident deaths and used medical records to confirm deaths due to cardiovascular, cancer, or female-specific cancer causes. We used multivariable Cox proportional hazards models to estimate the effect of migraine or headache status on both all-cause and cause-specific mortality.

RESULTS

Compared to individuals without any headache, no differences in all-cause mortality for individuals suffering from non-migraine headache or any migraine were observed after adjustment for confounding (HR = 1.01, 95%CI, 0.93-1.10 and HR = 0.96, 95% CI: 0.89-1.04). No differences were observed for the migraine subtypes and all-cause death. Women having the migraine with aura subtype had  a higher mortality due to cardiovascular disease (adjusted HR = 1.64, 95%CI: 1.06-2.54). As an explanation for the lack of overall association with all-cause mortality, we observed slightly protective signals for any cancer and female-specific cancers in this group.

CONCLUSIONS

In this large prospective study of women, we found no association between non-migraine headache or migraine and all-cause mortality. Women suffering from migraine with aura had an increased risk of cardiovascular death. Future studies should investigate the reasons for the increased risk of cardiovascular mortality and evaluate whether changes in migraine patterns across the life course have differential effects on mortality.

An investigation of oxidant/antioxidant balance in patients with migraine: a case-control study

BACKGROUND

In recent years, the role of neuroinflammation and oxidative stress in migraine pathogenesis has achieved considerable interest; however, to date findings are equivocal. Thus, the objective of this study was to investigate biomarkers of oxidative stress in episodic and chronic migraineurs (EM and CM patients) and controls.

METHODS

Forty-four patients with EM, 27 individuals with CM and 19 age-sex-matched controls were enrolled. After collecting data on demographic and headache characteristics, blood samples were collected and analyzed to detect serum levels of oxidative stress biomarkers (malondialdehyde (MDA) and nitric oxide (NO)); total antioxidant capacity using Trolox equivalent antioxidant capacity (TEAC) assay; and antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase-1 (GPx-1)).

RESULTS

Serum levels of CAT and SOD were significantly lower in the CM group than the EM group and controls. However, serum GPx-1 levels of the CM patients were slightly higher than the EM patients and controls (P-value≤0.001). CM patients had lower mean TEAC values than EM patients and controls. In addition, serum levels of NO and MDA were significantly elevated among subjects with CM compared to EM and control individuals (P-value≤0.001). Pearson correlation analysis revealed negative correlations between the number of days of having headaches per month and serum concentrations of the two antioxidant enzymes CAT (r = - 0.60, P-value< 0.001) and SOD (r = - 0.50, P-value< 0.001) as well as TEAC values (r = - 0.61, P-value< 0.001); however, there were positive correlations between headache days and serum GPx-1 levels (r = 0.46, P-value< 0.001), NO (r = 0.62, P-value< 0.001), and MDA (r = 0.64, P-value< 0.001).

CONCLUSION

Present findings highlighted that chronic migraineurs had lower total non-enzymatic antioxidant capacity and higher oxidative stress than episodic migraineurs and control individuals. Although more studies are needed to confirm these data, applying novel prophylactic medications or dietary supplements with antioxidant properties could be promising in migraine therapy.

Association of diet and headache

The global prevalence of migraine as a primary headache has been estimated as 14.4% in both sexes. Migraine headache has been ranked as the highest contributor to disability in under 50 years old population in the world. Extensive research has been conducted in order to clarify the pathological mechanisms of migraine. Although uncertainties remains, it has been indicated that vascular dysfunction, cortical spreading depression (CSD), activation of the trigeminovascular pathway, pro-inflammatory and oxidative state may play a putative role in migraine pain generation. Knowledge about pathophysiological mechanisms of migraine should be integrated into a multimodal treatment approach to increase quality of life in patients. With respect to this, within the integrative health studies growing interest pertains to dietary interventions. Although the number of studies concerning effects of diet on headache/migraine is not yet very large, the current article will review the available evidence in this area. All publications on headache/migraine and dietary interventions up to May 2019 were included in the present review through a PubMed/MEDLINE and ScienceDirect database search. According to the current findings, Ketogenic diet and modified Atkins diet are thought to play a role in neuroprotection, improving mitochondrial function and energy metabolism, compensating serotoninergic dysfunction, decreasing calcitonin gene-related peptide (CGRP) level and suppressing neuro-inflammation. It can also be speculated that prescription of low glycemic diet may be promising in headache/migraine control through attenuating the inflammatory state. Moreover, obesity and headaches including migraine could be attributed to each other through mechanisms like inflammation, and irregular hypothalamic function. Thereby, applying dietary strategies for weight loss may also ameliorate headache/migraine. Another important dietary intervention that might be effective in headache/migraine improvement is related to balance between the intake of essential fatty acids, omega-6 and omega-3 which also affect inflammatory responses, platelet function and regulation of vascular tone. Regarding elimination diets, it appears that targeted these diets in migraine patients with food sensitivities could be effective in headache/migraine prevention. Taken together, dietary approaches that could be considered as effective strategies in headache/migraine prophylaxis include weight loss diets in obese headache patients, ketogenic and low-calorie diets, reducing omega-6 and increasing omega-3 fatty acid intakes.

Vitamin D in migraine headache: a comprehensive review on literature

INTRODUCTION

As a primary headache, migraine has been established as the first leading disability cause worldwide in the subjects who aged less than 50 years. A variety of dietary supplements have been introduced for migraine complementary treatment. As an anti-inflammatory and antioxidant agent, vitamin D is one of these agents which has been of interest in recent years. Although higher prevalence of vitamin D deficiency/insufficiency has been highlighted among migraineurs compared to controls, there is not any consensus in prescribing vitamin D in clinical practice. Therefore, in the current review, in addition to observational and case-control studies, we also included clinical trials concerning the effects of vitamin D supplementation on migraine/headache.

METHODS

Based on a PubMed/MEDLINE and ScienceDirect database search, this review study includes published articles up to June 2019 concerning the association between migraine/headache and vitamin D status or supplementation.

RESULTS

The percentage of subjects with vitamin D deficiency and insufficiency among migraineurs and headache patients has been reported to vary between 45 and 100%. In a number of studies, vitamin D level was negatively correlated with frequency of headaches. The present findings show that supplementation with this vitamin in a dose of 1000-4000 IU/d could reduce the frequency of attacks in migraineurs.

CONCLUSION

It seems a high proportion of migraine patients might suffer from vitamin D deficiency/insufficiency. Further, the current evidence shows that in addition to routine drug therapy, vitamin D administration might reduce the frequency of attacks in migraineurs. However, these results have yet to be confirmed.

The synergistic effects of nano-curcumin and coenzyme Q10 supplementation in migraine prophylaxis: a randomized, placebo-controlled, double-blind trial

Introduction: Migraine is a disabling neurovascular disorder characterized by increasing levels of pro-inflammatory cytokines and oxidative stress biomarkers. Curcumin and coenzyme Q10 (CoQ10) can exert neuroprotective effects through modulation of inflammation and oxidative stress. The aim of the present study was to evaluate the combined effects of nano-curcumin and CoQ10 supplementation on migraine symptoms and quality of life in migraine patients.Methods: One-hundred men and women (mean age 32 years) with episodic migraine based on the International Headache Society (IHS) criteria participated in this study. The subjects were randomly divided into four groups as (1) combination of nano-curcumin (80 mg) plus CoQ10 (300 mg), (2) nano-curcumin (80 mg), (3) CoQ10 (300 mg) and (4) the control (nano-curcumin and CoQ10 placebo included oral paraffin oil) beside usual prophylactic drugs for 8 weeks. Frequency, severity, duration of headache attacks, the headache diary results (HDR) and headache disability based on migraine-specific questionnaires were assessed at the baseline and end of the study.Results: Ninety-one of 100 patients completed the study. The results showed a significant effect of nano-curcumin and CoQ10 supplementation on frequency, severity, duration of migraine attacks and HDR compared to other groups (All P < 0.001). Nano-curcumin and CoQ10 group also had better scores in migraine-specific questionnaires at the end of the study compared to other groups (All P < 0.001). There were no side effects reported by the participants.Conclusions: These findings suggest a possible synergistic effect of nano-curcumin and CoQ10 on clinical features of migraine.Trial registration number: IRCT2017080135444N1.

Large-scale plasma metabolome analysis reveals alterations in HDL metabolism in migraine

OBJECTIVE

To identify a plasma metabolomic biomarker signature for migraine.

METHODS

Plasma samples from 8 Dutch cohorts (n = 10,153: 2,800 migraine patients and 7,353 controls) were profiled on a ¹H-NMR-based metabolomics platform, to quantify 146 individual metabolites (e.g., lipids, fatty acids, and lipoproteins) and 79 metabolite ratios. Metabolite measures associated with migraine were obtained after single-metabolite logistic regression combined with a random-effects meta-analysis performed in a nonstratified and sex-stratified manner. Next, a global test analysis was performed to identify sets of related metabolites associated with migraine. The Holm procedure was applied to control the family-wise error rate at 5% in single-metabolite and global test analyses.

RESULTS

Decreases in the level of apolipoprotein A1 (β -0.10; 95% confidence interval [CI] -0.16, -0.05; adjusted p = 0.029) and free cholesterol to total lipid ratio present in small high-density lipoprotein subspecies (HDL) (β -0.10; 95% CI -0.15, -0.05; adjusted p = 0.029) were associated with migraine status. In addition, only in male participants, a decreased level of omega-3 fatty acids (β -0.24; 95% CI -0.36, -0.12; adjusted p = 0.033) was associated with migraine. Global test analysis further supported that HDL traits (but not other lipoproteins) were associated with migraine status.

CONCLUSIONS

Metabolic profiling of plasma yielded alterations in HDL metabolism in migraine patients and decreased omega-3 fatty acids only in male migraineurs.

Effect of coenzyme Q10 supplementation on clinical features of migraine: a systematic review and dose-response meta-analysis of randomized controlled trials

Objective: Coenzyme Q10 is an antioxidant and an essential mitochondrial cofactor which has been suggested to improve the clinical features of migraine. Several randomized clinical trials have examined the effects of Coenzyme Q10 on migraine with inconclusive results. The aim of this systematic review and meta-analysis was to evaluate the impact of Coenzyme Q10 supplementation on the frequency, severity, and duration of migraine attacks. Methods: A systematic review of the literature was conducted using ISI Web of Science, PubMed, Cochrane library and Scopus to identify eligible studies up to April 2018. Studies included were randomized clinical trials of Coenzyme Q10 supplementation that reported the frequency, severity, or duration of migraine attacks as a primary outcome. A meta-analysis of eligible studies was performed using the fixed effects model or the random effects model to estimate pooled effect size. Results: Four randomized clinical trials with 221 participants were included. Coenzyme Q10 supplementation significantly reduced the frequency of migraine attacks (weighted mean difference: -1.87 attacks/month, 95% CI: -2.69 to -1.05, p < 0.001) without significant heterogeneity among the studies (I ² = 36.6%, p = 0.192). Coenzyme Q10 supplementation had no significant effect on severity (weighted mean difference: -2.35 visual analog scale score, 95% CI: -5.19 to 0.49, p = 0.105) and duration of migraine attacks (weighted mean difference: -6.14 h, 95% CI: -13.14 to 0.87, p = 0.086) with high heterogeneity. Conclusion: Pooled analyses of available randomized clinical trials suggest that Coenzyme Q10 supplementation may reduce the frequency of migraine attacks per month without affecting the severity or duration of migraine attacks.

Migraine and Markers of Carotid Atherosclerosis in Middle-Aged Women: A Cross-Sectional Study

OBJECTIVE

This study evaluated the association between migraine and the markers of carotid artery disease.

BACKGROUND

Migraine increases the risk of cardiovascular events, but its relationship with vascular dysfunction is unclear.

METHODS

In this cross-sectional study, middle-aged women with no known cardiovascular diseases underwent clinical, neurological, and laboratory evaluations; pulse wave velocity (PWV) assessment; and carotid artery ultrasonography. We divided the participants based on the presence of migraine and, further, based on the type of migraine. Associations between migraine and carotid thickening (intima-media thickness >0.9 mm), carotid plaques, or arterial stiffening (PWV >10 m/s) were evaluated using a multiple regression analysis.

RESULTS

The study comprised 112/277 (40%) women with migraine, of whom 46/277 (17%) reported having an aura. Compared to the non-migraineurs, the migraine with aura group had an increased risk of diffuse carotid thickening (3/46 [6.8%] vs 2/165 [1.3%], adjusted OR = 7.12, 95% CI 1.05-48.49). Migraine without aura was associated with a low risk of carotid plaques (3/66 [4.7%] vs 26/165 [16.7%], adjusted OR = 0.28, 95% CI 0.08-0.99) and arterial stiffening (21/66 [34.4%] vs 82/165 [51.2%], adjusted OR = 0.39, 95% CI 0.19-0.79). There were no correlations between migraine characteristics and arterial stiffness or carotid thickness measurements.

CONCLUSION

Migraine with aura is associated with an increased risk of carotid thickening, and migraine without aura is associated with a low risk of carotid plaques and arterial stiffening.

Association of white matter hyperintensities with migraine features and prognosis

Background

White matter hyperintensities (WMHs) are frequently detected in migraine patients. However, their significance and correlation to migraine disease burden remain unclear. This study aims to examine the correlation of WMHs with migraine features and explore the relationship between WMHs and migraine prognosis.

Methods

A total of 69 migraineurs underwent MRI scans to evaluate WMHs. Migraine features were compared between patients with and without WMHs. After an average follow-up period of 3 years, these patients were divided into two groups, according to the reduction of headache frequency: improved and non-improved groups. The percentage and degree of WMHs were compared between these two groups.

Results

A total of 24 patients (34.8%) had WMHs. Patients with WMHs were significantly older (39.0 ± 7.9 vs. 30.6 ± 10.4 years, P < 0.001) and had a longer disease duration (median: 180.0 vs. 84.0 months, P = 0.013). Furthermore, 33 patients completed the follow up period (15 patients improved and 18 patients did not improve). Patients in the non-improved group had a higher frequency of WMHs (55.6% vs. 13.3%, P = 0.027) and median WMHs score (1.0 vs. 0.0, P = 0.030).

Conclusions

WMHs can predict unfavorable migraine prognosis. Furthermore, WMHs may have a closer association with age than migraine features.

CGRP and PTX3 as Predictors of Efficacy of Onabotulinumtoxin Type A in Chronic Migraine: An Observational Study

OBJECTIVE

The aim of this study is to find a relation between several biomarkers in peripheral blood and outcome after treatment with onabotulinumtoxin A (OnabotA).

BACKGROUND

OnabotA is an effective treatment in chronic migraine (CM). Different studies have tried to find predictors of response to treatment, either with clinical characteristics, neuroimaging features, or molecular biomarkers; however, it is still not possible to predict the individual outcome.

METHODS

We measured serum levels of biomarkers of inflammation (IL-6, IL-10, TNF-α, and hs-CRP), endothelial dysfunction (PTX3 and sTWEAK), blood-brain barrier disruption (cFN), brain damage (S100b, NSE), and trigemino-vascular activation (CGRP) by ELISA in a group of CM patients treated with OnabotA and healthy controls. After 24 weeks, patients were classified in two groups according to their outcome considering variations in headache frequency: nonresponders (nonimprovement or improvement <50%) and responders (improvement >50%). We compared baseline levels of biomarkers between these groups.

RESULTS

Sixty-two patients diagnosed with CM (IHS 2013 criteria) who fulfilled criteria for treatment with OnabotA and 24 healthy controls were included. Fifteen patients did not respond to treatment (24.2%) and 47 were responders (75.8%). Pentraxin 3 (PTX3) serum levels (1455.4 ± 487.5 pg/mL versus 720.3 ± 334.1 pg/mL, P < .0001) and calcitonin gene-related peptide (CGRP) serum levels (133.1 ± 86.6 ng/mL versus 58.2 ± 91.7 ng/mL, P = .004) were significantly higher in responders than nonresponders. Serum basal levels of PTX3 >1000 pg/mL (AUC 0.908; 95% CI: 0.827-0.990) and CGRP >50 ng/mL (AUC 0.800; 95% CI: 0.652-0.947) were associated with good response to OnabotA treatment.

CONCLUSIONS

These results show that molecular markers of trigeminovascular activation (CGRP) and endothelial dysfunction (PTX3) are associated with response to OnabotA and may act as new biomarkers for the selection of treatment in chronic migraineurs.

Migraine and vascular disease biomarkers: A population-based case-control study

Background The underpinnings of the migraine-stroke association remain uncertain, but endothelial activation is a potential mechanism. We evaluated the association of migraine and vascular disease biomarkers in a community-based population. Methods Participants (300 women, 117 men) were recruited as a part of the Dutch CAMERA 1 (Cerebral Abnormalities in Migraine, an Epidemiologic Risk Analysis) study. Participants were aged 30-60 (mean 48) years, 155 migraine had with aura (MA), 128 migraine without aura (MO), and 134 were controls with no severe headaches. Plasma concentrations of fibrinogen, Factor II, D-dimer, high sensitivity C-reactive protein (hs-CRP), and von Willebrand factor antigen were compared between groups, also stratifying by sex. Results Fibrinogen and hs-CRP were elevated in migraineurs compared to controls. In logistic regression analyses, MO and MA had increased likelihood of elevated fibrinogen, and MA had increased likelihood of elevated Factor II and hs-CRP. Fibrinogen and Factor II were associated with MA in women but not men. In the migraine subgroup, the total number of years of aura, but not headache, predicted elevated hs-CRP, and the average number of aura, but not headache, attacks predicted all biomarkers but Factor II. Conclusions Elevated vascular biomarkers were associated with migraine, particularly MA, as well as with years of aura and number of aura attacks.

Periodontal disease as a potential factor of migraine chronification

Migraine is a hereditary constitutional base disorder, which is characterized by recurrent episodes of headache pulsatile characteristics associated with photophobia/phonophobia, nausea and/or vomiting. The main complication in migraine is the chronicity of the process, now recognized as a chronic migraine. Although pathogenic mechanisms that may influence the pathophysiology of migraine and its possible chronicity are not fully understood, previous studies have shown in patients with migraine molecular alterations of systemic inflammation, neurogenic inflammation, endothelial dysfunction, innate immunity, dysfunction of matrix proteases and blood-brain barrier. Periodontal disease is an inflammatory lesion caused by bacteria. After the bacterial infection begins, an immune response that will be responsible for individual susceptibility appears. More advanced forms of periodontitis have demonstrated molecular alterations of inflammation, endothelial dysfunction, dysfunction of matrix proteases and innate immunity, similar to those observed in migraine. Furthermore, the main molecular mediators of neurogenic inflammation related to activation of the trigeminovascular system, which are characteristic of migraine, are overexpressed in gingival crevicular fluid and mucosa in patients with periodontal disease. Hypertension, hypercholesterolemia, insulin resistance, stroke or coronary artery disease are comorbidities that periodontal disease and migraine could share. Therefore, several mechanisms and hypotheses could explain the possible association between both diseases. However, epidemiological and molecular studies will be necessary to provide a better understanding of this potential association, which could be implicated in the chronification of migraine.

Delivery Outcomes of Patients with Acute Migraine in Pregnancy: A Retrospective Study

OBJECTIVE

To describe labor and delivery outcomes in pregnant patients presenting to the hospital setting with an acute severe migraine headache attack earlier in the same gestation.

METHODS

We retrospectively reviewed pregnancy and delivery records from a database of consecutive inpatient neurology consultations for acute headache in pregnant women over a 5 year period.

RESULTS

We identified 86 pregnant women with acute migraine. The mean age was 29.3 (±6.4) years. Nearly half had migraine with aura (35/86 [40.7%]), 12.8% (12/86) had chronic migraine, and 31.4% (27/86) presented in status migrainosus. Complication rates included 54.7%([41/75], 95% CI 29.87, 52.13) for at least one adverse outcome, 28.0% ([21/75], 95% CI 11.78, 30.22) for preterm delivery, 21.3% ([16/75], 95% CI 7.7, 24.3) for preeclampsia, 30.6% ([23/75] 95% CI 13.48, 32.52) for cesarean delivery, and 18.7% ([14/75] 95% CI 6.15, 21.85) for low birthweight.

CONCLUSIONS

Pregnant women seeking treatment for acute migraine headache experienced a higher rate of preterm delivery, preeclampsia, and low birthweight but a lower rate of cesarean delivery than the local and general populations. More than half (54.7% [41/75] 95% CI 29.87, 52.13) of the study patients experienced some type of adverse birth outcome, suggesting that pregnancies in migraine patients presenting to an acute care setting may benefit from more intense surveillance.

Neurovascular contributions to migraine: Moving beyond vasodilation

Migraine is the third most common disease worldwide, the most common neurological disorder, and one of the most common pain conditions. Despite its prevalence, the basic physiology and underlying mechanisms contributing to the development of migraine are still poorly understood and development of new therapeutic targets is long overdue. Until recently, the major contributing pathophysiological event thought to initiate migraine was cerebral and meningeal arterial vasodilation. However, the role of vasodilation in migraine is unclear and recent findings challenge its necessity. While vasodilation itself may not contribute to migraine, it remains possible that vessels play a role in migraine pathophysiology in the absence of vasodilation. Blood vessels consist of a variety of cell types that both release and respond to numerous mediators including growth factors, cytokines, adenosine triphosphate (ATP), and nitric oxide (NO). Many of these mediators have actions on neurons that can contribute to migraine. Conversely, neurons release factors such as norepinephrine and calcitonin gene-related peptide (CGRP) that act on cells native to blood vessels. Both normal and pathological events occurring within and between vascular cells could thus mediate bi-directional communication between vessels and the nervous system, without the need for changes in vascular tone. This review will discuss the potential contribution of the vasculature, specifically endothelial cells, to current neuronal mechanisms hypothesized to play a role in migraine. Hypothalamic activity, cortical spreading depression (CSD), and dural afferent input from the cranial meninges will be reviewed with a focus on how these mechanisms can influence or be impacted by blood vessels. Together, the data discussed will provide a framework by which vessels can be viewed as important potential contributors to migraine pathophysiology, even in light of the current uncertainty over the role of vasodilation in this disorder.

Adipokines and Migraine: A Systematic Review

BACKGROUND

Migraine is comorbid with obesity. Recent research suggests an association between migraine and adipocytokines, proteins that are predominantly secreted from adipose tissue and which participate in energy homeostasis and inflammatory processes.

OBJECTIVES

In this review, we first briefly discuss the association between migraine and obesity and the importance of adipose tissue as a neuroendocrine organ. We then present a systematic review of the extant literature evaluating circulating levels of adiponectin and leptin in those with migraine.

METHODS

A search of the PubMed database was conducted using the keywords "migraine," "adiponectin," and "leptin." In addition reference lists of relevant articles were reviewed for possible inclusion. English language studies published between 2005 and 2015 evaluating circulating blood concentration of adiponectin or leptin in those with migraine were included.

CONCLUSIONS

While the existing data are suggestive that adipokines may be associated with migraine, substantial study design differences and conflicting results limit definitive conclusions. Future research utilizing carefully considered designs and methodology is warranted. In particular careful and systematic characterization of pain states at the time of samples, as well as systematic consideration of demographic (e.g., age, sex) and other vital covariates (e.g., obesity status, lipids) are needed to determine if adipokines play a role in migraine pathophysiology and if any adipokine represents a viable, novel migraine biomarker, or drug target.

Mechanisms mediating nitroglycerin-induced delayed-onset hyperalgesia in the rat

Nitroglycerin (glycerol trinitrate, GTN) induces headache in migraineurs, an effect that has been used both diagnostically and in the study of the pathophysiology of this neurovascular pain syndrome. An important feature of this headache is a delay from the administration of GTN to headache onset that, because of GTN's very rapid metabolism, cannot be due to its pharmacokinetic profile. It has recently been suggested that activation of perivascular mast cells, which has been implicated in the pathophysiology of migraine, may contribute to this delay. We reported that hyperalgesia induced by intradermal GTN has a delay to onset of ∼ 30 min in male and ∼ 45 min in female rats. This hyperalgesia was greater in females, was prevented by pretreatment with the anti-migraine drug, sumatriptan, as well as by chronic pretreatment with the mast cell degranulator, compound 48/80. The acute administration of GTN and compound 48/80 both induced hyperalgesia that was prevented by pretreatment with octoxynol-9, which attenuates endothelial function, suggesting that GTN and mast cell-mediated hyperalgesia are endothelial cell-dependent. Furthermore, A-317491, a P2X3 antagonist, which inhibits endothelial cell-dependent hyperalgesia, also prevents GTN and mast cell-mediated hyperalgesia. We conclude that delayed-onset mechanical hyperalgesia induced by GTN is mediated by activation of mast cells, which in turn release mediators that stimulate endothelial cells to release ATP, to act on P2X3, a ligand-gated ion channel, in perivascular nociceptors. A role of the mast and endothelial cell in GTN-induced hyperalgesia suggests potential novel risk factors and targets for the treatment of migraine.

Clinical impact of migraine for the management of glaucoma patients

Migraine is a common and debilitating primary headache disorder that affects 10-15% of the general population, particularly people of working age. Migraine is relevant to providers of clinical eye-care because migraine attacks are associated with a range of visual sensory symptoms, and because of growing evidence that the results of standard tests of visual function necessary for the diagnosis and monitoring of glaucoma (visual fields, electrophysiology, ocular imaging) can be abnormal due to migraine. These abnormalities are measureable in-between migraine events (the interictal period), despite patients being asymptomatic and otherwise healthy. This picture is further complicated by epidemiological data that suggests an increased prevalence of migraine in patients with glaucoma, particularly in patients with normal tension glaucoma. We discuss how migraine, as a co-morbidity, can confound the results and interpretation of clinical tests that form part of contemporary glaucoma evaluation, and provide practical evidence-based recommendations for the clinical testing and management of patients with migraine who attend eye-care settings.