Increased matrix metalloproteinase activity is associated with migraine and migraine-related metabolic dysfunctions

Altered immunity in migraine: a comprehensive scoping review

BACKGROUND

The pathogenesis of migraine remains unclear; however, a large body of evidence supports the hypothesis that immunological mechanisms play a key role. Therefore, we aimed to review current studies on altered immunity in individuals with migraine during and outside attacks.

METHODS

We searched the PubMed database to investigate immunological changes in patients with migraine. We then added other relevant articles on altered immunity in migraine to our search.

RESULTS

Database screening identified 1,102 articles, of which 41 were selected. We added another 104 relevant articles. We found studies reporting elevated interictal levels of some proinflammatory cytokines, including IL-6 and TNF-α. Anti-inflammatory cytokines showed various findings, such as increased TGF-β and decreased IL-10. Other changes in humoral immunity included increased levels of chemokines, adhesion molecules, and matrix metalloproteinases; activation of the complement system; and increased IgM and IgA. Changes in cellular immunity included an increase in T helper cells, decreased cytotoxic T cells, decreased regulatory T cells, and an increase in a subset of natural killer cells. A significant comorbidity of autoimmune and allergic diseases with migraine was observed.

CONCLUSIONS

Our review summarizes the findings regarding altered humoral and cellular immunological findings in human migraine. We highlight the possible involvement of immunological mechanisms in the pathogenesis of migraine. However, further studies are needed to expand our knowledge of the exact role of immunological mechanisms in migraine pathogenesis.

Exercise training reduces systemic inflammation and improves general health status in female migraineurs: a randomised controlled trail

OBJECTIVES

The objectives of this study were to assess the effect of 8 weeks of moderate-intensity aerobic training on permeability inflammatory indicators of matrix metalloproteinases (MMPs) and specific tissue inhibitors of MMPs in female migraineurs.

METHODS

Female migraineurs (n = 28, age 32 ± 6) were randomised into two groups: migraine with exercise training (EXE + Mig, n = 13) and migraine without exercise training (NON-EXE + Mig, n = 15). Matched healthy women were also recruited as a healthy control group (CON, n = 15). The EXE-Mig group performed 8 weeks of aerobic training. Pre and post intervention, serum matrix metalloproteinases (MMP-2 and 9) and specific tissue inhibitors of MMPs (TIMP-1 and 2) were measured. In addition, body composition indices and VO2max were determined.

RESULTS

Exercise training reduced serum MMP-9 in female migraineurs with between-group changes and a time x group interaction (p < 0.05). In addition, exercise training reduced the serum MMP-9/TIMP-1 ratio in female migraineurs with between-group changes and time x group interaction (p < 0.05). However, no training-induced effect was observed in serum TIMP-1, TIMP-2, MMP-2 contents (p > 0.05) and MMP-2/TIMP-2 ratio (p > 0.05). Finally, exercise training reduced body fat content, WHR and BMI, and improved VO2max (p < 0.01).

CONCLUSIONS

Our results demonstrated beneficial effects of aerobic exercise training on some circulatory inflammation factors (MMP9, MMP-9/TIMP-1) and some health indicators in female migraineurs, suggesting that such training can be employed as a non-pharmacological therapeutic method.

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.

Migraine and obesity: what is the real direction of their association?

INTRODUCTION

In recent decades, studies have addressed the issue of how migraine and obesity are related and have suggested obesity as a risk factor for migraine headache. However, the exact direction of this relationship remains under debate. In this review, the authors summarize the evidence that have suggested migraine as a risk factor for obesity and overweightness.

AREAS COVERED

This article reviews the results of the previous research published on PubMed and Scopus databases (from 2000 to 2020) concerning the association between migraine and obesity to determine the actual direction of their association. Special attention has been given to the common mechanistic pathways involved in the pathophysiology of migraine and obesity.

EXPERT OPINION

The majority of research conducted thus far has considered obesity as a risk factor for migraine. However, because of the cross-sectional design of available research, we cannot be certain of the proposed direction of this association. There is evidence supporting the hypothesis that obesity can serve as a consequence of migraine through the effects of neuropeptides, inflammatory mediators, adipokines, gut microbiota and modifications in eating behavior and lifestyle. However, the real direction of the relationship between migraine and obesity should be further investigated in large prospective studies.

Imaging the inflammatory phenotype in migraine

Several preclinical and clinical lines of evidence suggest a role of neuroinflammation in migraine. Neuroimaging offers the possibility to investigate and localize neuroinflammation in vivo in patients with migraine, and to characterize specific inflammatory constituents, such as vascular permeability, and macrophage or microglia activity. Despite all imaging data accumulated on neuroinflammation across the past three decades, an overview of the imaging evidence of neuroinflammation in migraine is still missing.We conducted a systematic review in the Pubmed and Embase databases to evaluate existing imaging data on inflammation in migraine, and to identify gaps in the literature. We included 20 studies investigating migraine without aura (N = 4), migraine with aura (N = 8), both migraine with and without aura (N = 3), or hemiplegic migraine (N = 5).In migraine without aura, macrophage activation was not evident. In migraine with aura, imaging evidence suggested microglial and parameningeal inflammatory activity. Increased vascular permeability was mostly found in hemiplegic migraine, and was atypical in migraine with and without aura. Based on the weight of existing and emerging data, we show that most studies have concentrated on demonstrating increased vascular permeability as a marker of neuroinflammation, with tools that may not have been optimal. In the future, novel, more sensitive techniques, as well as imaging tracers delineating specific inflammatory pathways may further bridge the gap between preclinical and clinical findings.

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.

Genetics, pathophysiology, diagnosis, treatment, management, and prevention of migraine

Migraine is a neurological ailment that is characterized by severe throbbing unilateral headache and associated with nausea, photophobia, phonophobia and vomiting. A full and clear mechanism of the pathogenesis of migraine, though studied extensively, has not been established yet. The current available information indicates an intracranial network activation that culminates in the sensitization of the trigemino-vascular system, release of inflammatory markers, and initiation of meningeal-like inflammatory reaction that is sensed as headache. Genetic factors might play a significant role in deciding an individual's susceptibility to migraine. Twin studies have revealed that a single gene polymorphism can lead to migraine in individuals with a monogenic migraine disorder. In this review, we describe recent advancements in the genetics, pathophysiology, diagnosis, treatment, management, and prevention of migraine. We also discuss the potential roles of genetic and abnormal factors, including some of the metabolic triggering factors that result in migraine attacks. This review will help to accumulate current knowledge about migraine and understanding of its pathophysiology, and provides up-to-date prevention strategies.

Acute Exercise in Hypobaric Hypoxia Attenuates Endothelial Shedding in Subjects Unacclimatized to High Altitudes

Travel of unacclimatized subjects to a high altitude has been growing in popularity. Changes in endothelial shedding [circulating endothelial cells (ECs)] and hematopoietic stem and progenitor cells (CPCs) during physical exercise in hypobaric hypoxia, however, are not well understood. We investigated the change in ECs and CPCs when exposed to high altitude, after acute exercise therein, and after an overnight stay in hypobaric hypoxia in 11 healthy unacclimatized subjects. Blood withdrawal was done at baseline (520 m a.s.l.; baseline), after passive ascent to 3,883 m a.s.l. (arrival), after acute physical exercise (±400 m, postexercise) and after an overnight stay at 3,883 m a.s.l. (24 h). Mature blood cells, ECs, and CPCs were assessed by a hematology analyzer and flow cytometry, respectively. The presence of matrix metalloproteinases (MMPs), their activity, and hematopoietic cytokines were assessed in serum and plasma. EC and CPC concentrations significantly decreased after exercise (p = 0.019, p = 0.007, respectively). CPCs remained low until the next morning (24 h, p = 0.002), while EC concentrations returned back to baseline. MMP-9 decreased at arrival (p = 0.021), stayed low postexercise (p = 0.033), and returned to baseline at 24 h (p = 0.035 to postexercise). MMP-activity did not change throughout the study. Circulating MMP-9 concentrations, but not MMP-activity, were associated with EC concentrations (r_rm = 0.48, p = 0.010). CPC concentrations were not linked to hematopoietic cytokines. Acute exercise at high altitude attenuated endothelial shedding, but did not enhance regenerative CPCs. Results were not linked to endothelial matrix remodeling or CPC mobilization. These results provide information to better understand the endothelium and immature immune system during an active, short-term sojourn at high altitude.

Are Migraine With and Without Aura Really Different Entities?

Background: Migraine research is booming with the rapidly developing neuroimaging tools. Structural and functional alterations of the migrainous brain were detected with MRI. The outcome of a research study largely depends on the working hypothesis, on the chosen measurement approach and also on the subject selection. Against all evidence from the literature that migraine subtypes are different, most of the studies handle migraine with and without aura as one disease. Methods: Publications from PubMed database were searched for terms of "migraine with aura," "migraine without aura," "interictal," "MRI," "diffusion weighted MRI," "functional MRI," "compared to," "atrophy" alone and in combination. Conclusion: Only a few imaging studies compared the two subforms of the disease, migraine with aura, and without aura, directly. Functional imaging investigations largely agree that there is an increased activity/activation of the brain in migraine with aura as compared to migraine without aura. We propose that this might be the signature of cortical hyperexcitability. However, structural investigations are not equivocal. We propose that variable contribution of parallel, competing mechanisms of maladaptive plasticity and neurodegeneration might be the reason behind the variable results.

Leptin, adiponectin, and resistin blood adipokine levels in migraineurs: Systematic reviews and meta-analyses

INTRODUCTION

Migraine comorbidity with obesity is not new and studies have focused on how adipose tissue-derived substances such as adipokines might be involved in the migraine pathophysiology. Quantification of the nature and magnitude of the association between each adipokine including leptin, adiponectin and resistin with migraine pathophysiology is the objective of the current study.

METHODS

Using systematic reviews and meta-analyses and standardized mean difference as effect size, the levels of three adipokines, leptin, adiponectin and resistin, have been investigated in migraineur subjects in the case-control studies.

RESULTS

Using random-effects models, the final analyses demonstrated the standardized mean differences of leptin, adiponectin and resistin as 0.534 (95% confidence interval, 0.169-0.898), 0.439 (95% confidence interval, 0.132-0.746) and 0.194 (95% confidence interval, -0.158-0.546), respectively. The p-value for test of significance for each pooled standardized mean difference was examined by the z-test and calculated as 0.004, 0.005 and 0.281 for leptin, adiponectin and resistin (clearly considered as statistically significant, significant and non-significant), respectively.

CONCLUSION

Based on the findings, the blood levels of leptin and adiponectin, but not resistin, of the migraineurs are associated with disease pathogenesis.

Gene Network Dysregulation in the Trigeminal Ganglia and Nucleus Accumbens of a Model of Chronic Migraine-Associated Hyperalgesia

The pharmacological agent nitroglycerin (NTG) elicits hyperalgesia and allodynia in mice. This model has been used to study the neurological disorder of trigeminovascular pain or migraine, a debilitating form of hyperalgesia. The present study validates hyperalgesia in an established mouse model of chronic migraine triggered by NTG and advances the understanding of the associated molecular mechanisms. The RNA-seq profiles of two nervous system regions associated with pain, the trigeminal ganglia (TG) and the nucleus accumbens (NAc), were compared in mice receiving chronic NTG treatment relative to control (CON) mice. Among the 109 genes that exhibited an NTG treatment-by-region interaction, solute carrier family 32 (GABA vesicular transporter) member 1 (Slc32a1) and preproenkephalin (Penk) exhibited reversal of expression patterns between the NTG and CON groups. Erb-b2 receptor tyrosine kinase 4 (Erbb4) and solute carrier family 1 (glial high affinity glutamate transporter) member 2 (Slc1a2) exhibited consistent differential expression between treatments across regions albeit at different magnitude. Period circadian clock 1 (Per1) was among the 165 genes that exhibited significant NTG treatment effect. Biological processes disrupted by NTG in a region-specific manner included adaptive and innate immune responses; whereas glutamatergic and dopaminergic synapses and rhythmic process were disrupted in both regions. Regulatory network reconstruction highlighted the widespread role of several transcription factors (including Snrnp70, Smad1, Pax6, Cebpa, and Smpx) among the NTG-disrupted target genes. These results advance the understanding of the molecular mechanisms of hyperalgesia that can be applied to therapies to ameliorate chronic pain and migraine.

Alpha-Lipoic Acid Shows Promise to Improve Migraine in Patients with Insulin Resistance: A 6-Month Exploratory Study

Alpha-lipoic acid (ALA) is known to lower insulin resistance (IR), which is common among migraineurs. To assess the effect of ALA on headache in migraineurs with IR, we performed an exploratory study on a cohort of patients with migraine, followed at our Headache Center. The 32 patients took ALA 400 mg b.i.d. for 6 months in addition to their on-going treatment. The percentage of patients with a reduction of at least 50% of the attacks was 0.53 (confidence interval [95% CI] 0.36-0.70) at 2 months, 0.56 (0.39-0.73) at 4 months, and 0.69 (0.53-0.85) at 6 months. The incidence rate ratio of attacks at 6 months versus baseline was 0.48 (0.43-0.53, P < .001), corresponding to a mean (95% CI) number of attacks of 5 (4-6) versus 11 (10-12). The number of days of treatment in the previous month was 7.7 (6.8-8.7) at baseline, 5.4 (4.6-6.2) at 2 months, 5.3 (4.5-6.1) at 4 months, and 4.3 (3.6-5.0) at 6 months. Baseline and 120-min glucose and insulin and quantitative insulin sensitivity check index (QUICKI) and the Stumvoll index did not change at 6 months versus baseline. This exploratory study shows that the administration of ALA may be associated with a reduction in the number of attacks and the days of treatment in migraineurs with IR. A randomized controlled trial is needed to test this possibility.

Role of adipocytokines in the pathophysiology of migraine: A cross-sectional study

Background Obesity is a risk factor for migraine and headache chronification. Adipocytokines may be involved in this correlation. Objective To relate serum adipocytokine levels to clinical and biochemical parameters associated with migraine. Methods We measured levels of leptin, adiponectin and other inflammatory (interleukin 6, interleukin 10, tumor necrosis factor α, high sensitivity C-reactive protein) and endothelial (pentraxin 3, soluble TNF-like weak inducer of apoptosis) molecules potentially related to migraine pathophysiology in a group of migraine patients (IHS 2013) and healthy controls. Results One hundred and eleven patients (mean age 39.7 years, 93% female) and 24 healthy controls (mean age 35.9 years, 90% female) were included. Fifty-six patients were diagnosed with episodic migraine (mean age 35.1 years, 98.2% female) and 55 patients with chronic migraine (mean age 44.4 years, 89.5% female). Leptin serum levels (15.2 ng/mL, SD = 10.5 vs . 3.1 ng/mL, SD = 0.9; p < 0.001) and adiponectin serum levels (72.3 µg/mL, SD = 38.5 vs . 37.7 µg/mL, SD = 16.9; p < 0.001) were significantly increased in migraine patients. Leptin serum levels (15.5 ng/mL, SD = 9.7 vs . 10.8 ng/mL, SD = 6.0; p < 0.001) and adiponectin serum levels (65.8 µg/mL, SD = 42.9 vs . 33.2 µg/mL, SD = 31.0; p < 0.001) were significantly higher in chronic compared to episodic migraine patients. We found a positive correlation between leptin levels and inflammatory biomarkers: IL6 (r = 0.498; p < 0.001), TNF-α (r = 0.389; p < 0.001), and hs-CRP (r = 0.422; p < 0.001). Conclusions Leptin and adiponectin are increased in migraineurs. There is a correlation between adipocytokine levels and other inflammation-related molecules. This suggests a potential role of adipocytokines in migraine pathophysiology and chronification.

The Link Between Migraine, Reversible Cerebral Vasoconstriction Syndrome and Cervical Artery Dissection

Headache is the common thread of migraine, reversible cerebral vasoconstriction syndrome (RCVS) and cervical artery dissection (CeAD), three medical conditions that otherwise appear to be very different. However, epidemiological, clinical and genetic data suggest that these conditions share common and complex features and are, at least partly, linked. The purpose of this manuscript is to review existing evidence for an association between migraine, RCVS and CeAD and discuss the potential underlying mechanisms.

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.

Dissecting the association between migraine and stroke

Migraine is a common disabling neurological disorder resulting from excessive cortical excitation and trigeminovascular afferent sensitization. In addition to aberrant neuronal processing, migraineurs are also at significant risk of vascular disease. Consequently, the impact of migraine extends well beyond the ictal headache and includes a well-documented association with acute ischemic stroke, particularly in young women with a history of migraine with aura. The association between migraine and stroke has been acknowledged for 40 years or more. However, examining the pathobiology of this association has become a more recent and critically important undertaking. The diversity of mechanisms underlying the association between migraine and stroke likely reflects the heterogenous nature of this disorder. Vasospasm, endothelial injury, platelet aggregation and prothrombotic states, cortical spreading depression, carotid dissection, genetic variants, and traditional vascular risk factors have been offered as putative mechanisms involved in migraine-related stroke risk. Assimilating these seemingly divergent pathomechanisms into a cogent understanding of migraine-related stroke will inform future studies and the development of new strategies for the prevention and treatment of migraine and stroke.

The role of the blood-brain barrier in the development and treatment of migraine and other pain disorders

The function of the blood-brain barrier (BBB) related to chronic pain has been explored for its classical role in regulating the transcellular and paracellular transport, thus controlling the flow of drugs that act at the central nervous system, such as opioid analgesics (e.g., morphine) and non-steroidal anti-inflammatory drugs. Nonetheless, recent studies have raised the possibility that changes in the BBB permeability might be associated with chronic pain. For instance, changes in the relative amounts of occludin isoforms, resulting in significant increases in the BBB permeability, have been demonstrated after inflammatory hyperalgesia. Furthermore, inflammatory pain produces structural changes in the P-glycoprotein, the major efflux transporter at the BBB. One possible explanation for these findings is the action of substances typically released at the site of peripheral injuries that could lead to changes in the brain endothelial permeability, including substance P, calcitonin gene-related peptide, and interleukin-1 beta. Interestingly, inflammatory pain also results in microglial activation, which potentiates the BBB damage. In fact, astrocytes and microglia play a critical role in maintaining the BBB integrity and the activation of those cells is considered a key mechanism underlying chronic pain. Despite the recent advances in the understanding of BBB function in pain development as well as its interference in the efficacy of analgesic drugs, there remain unknowns regarding the molecular mechanisms involved in this process. In this review, we explore the connection between the BBB as well as the blood-spinal cord barrier and blood-nerve barrier, and pain, focusing on cellular and molecular mechanisms of BBB permeabilization induced by inflammatory or neuropathic pain and migraine.

Vascular biomarkers in migraine

AIM

Migraine has been associated with stroke as well as with several non-atherosclerotic vascular conditions leading to discussions about the potential role of endothelium in the etiopathogenesis of migraine and migraine-associated stroke. We present a systematic review of the literature on vascular biomarkers in migraine, including those suggesting endothelial activation and damage.

METHODS

We conducted a systematic literature search from 1990 to 2013 using multiple research databases with the keywords "migraine," "headache," "vascular," and "biomarkers." We used selected inclusion and exclusion criteria to create a final pool of studies for this review.

RESULTS

The literature search identified a total of 639 citations of which 129 were included in our review. The final pool of clinical- and population-based studies assessed the level of various biomarkers (e.g. inflammatory, prothrombotic, endothelial activation, endothelial repair) in migraineurs of varying ages, gender, and demographic characteristics. Although for each biomarker there is at least one study suggesting an association with migraine, in many cases the quality of evidence is poor and there are conflicting studies showing no relationship. The results were, therefore, in each case inconclusive.

CONCLUSION

This systematic review indicated that in migraine populations there are a number of positive vascular biomarker studies, including some involving novel biomarkers such as endothelial microparticles and endothelial precursor cells. These lend insight into possible pathophysiological mechanisms by which migraine may be associated with stroke. More high-quality studies are needed to establish whether a true association between promising vascular biomarkers and migraine exists.

Insulin resistance in migraineurs: results from a case-control study

OBJECTIVES

Several studies have suggested an association between migraine and insulin resistance (IR) without adequately addressing the issue according to migraine type. We assessed IR in subjects with migraine with aura (MwA) and migraine without aura (MwoA) to estimate the consistency of the possible association.

METHODS

In a case-control study we included case subjects with MwA and MwoA, who were consecutively selected from those referred to our Regional Headache Center from September 2011 to February 2013, and age-matched control subjects selected using general practitioners' databases. IR was calculated by means of the homeostatic model assessment of IR (HOMA-IR), β-cell function (HOMA-B), and the quantitative insulin sensitivity check index (QUICKI) measuring glucose and insulin values in a blood sample collected in the morning after overnight fasting. Data regarding anthropometric measures, comorbidity risk factors, and migraine characteristics were also recorded.

RESULTS

We recruited 50 case subjects with MwA (38 women) and 50 with MwoA (40 women) and 50 control subjects (40 women). Proportions of arterial hypertension, cigarette smoking, hypercholesterolemia, use of oral contraceptives, and mean values of the body mass index (BMI) were similar in the three groups. We found significantly different glucose values among and within groups considering case subjects with MwA and MwoA and control subjects (4.9 ± 0.6 vs 4.7 ± 0.5 vs 4.6 ± 0.5 mmol/l; P  = 0.018) in the absence of any difference in insulin (53.1 ± 24.0 vs 56.7 ± 34.4 vs 53.8 ± 24.4 pmol/l; P  = 0.811), HOMA-IR (1.6 ± 0.8 vs 1.7 ± 1.0 vs 1.6 ± 0.7; P  = 0.765), HOMA-B (121.4 ± 71.1 vs 149.2 ± 93.8 vs 162.8 ± 109.7; P  = 0.107), and QUICKI (0.36 ± 0.03 vs 0.37 ± 0.03 vs 0.37 ± 0.03; P  = 0.877) values. The logistic regression model showed increased odds of MwA in subjects exposed to the highest tertile of glucose values. This association was confirmed in the adjusted model, in which case subjects with MwA were compared with those with MwoA but not with control subjects.

CONCLUSIONS

In contrast to what has been shown by the majority of the available studies, the results of our study do not support the association of migraine with IR. As our study was not population-based and several patients had low disease activity, these findings need further confirmation.

Matrix metalloproteinases in neuropathic pain and migraine: friends, enemies, and therapeutic targets

Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent endopeptidases that mediate extracellular matrix turnover and associated processes, such as cell survival, growth, and differentiation. This paper discusses important functions of MMP in the normal and injured nervous system, focusing on the role played by these proteases in neurological pain syndromes, most prominently in neuropathic pain and migraine headaches. In the past decade, metalloproteinases emerged as key modulators of neuropathic pain, with MMP-9 acting as an initiator of the neuropathic cascade. Increased MMP activity was detected in migraine patients, independent of aura, in tight association with metabolic derangements. The therapeutic implications of MMP inhibition are considered in the context of neurogenic pain regulation.

Specific matrix metalloproteinase 9 (MMP-9) haplotype affect the circulating MMP-9 levels in women with migraine

We investigated whether three relevant polymorphisms (C-1562T, microsatellite -90(CA)(14-24), and Q279R) in the MMP-9 gene, or MMP-9 haplotypes, are associated with migraine and affect MMP-9 and tissue inhibitor of MMPs (TIMP)-1 levels in patients with migraine. We studied 102 healthy women (controls) and 187 women with migraine (141 without aura - MWA, and 46 with aura - MA). Patients with MWA had higher plasma MMP-9 concentrations than patients with MA. Patients with MA had the highest TIMP-1 and lowest MMP-9/TIMP-1 ratios. The MMP-9 "C L Q" haplotype was associated with higher plasma MMP-9 concentrations in migraine patients.

Delayed development of visual motion processing in childhood migraine

Introduction: Altered visual processing has been observed in adult migraineurs. But because visual processing has not been studied in paediatric cases, it is not known whether such visual system alterations are already present in early development. We therefore used a dynamic visual task to investigate motion detection threshold in paediatric migraine.

Methods: Fourteen migraineurs and 21 controls participated in the study (age range: 8–17 years). The minimal percentage of coherently moving dot stimuli at which subjects were still able to detect coherent movement (absolute threshold) was determined using a random dot kinematogram paradigm.

Results: Motion coherence detection threshold was higher in migraineurs ( p < 0.05). This difference between groups was more pronounced at younger ages, but migraineurs seem to catch up with healthy controls over the years.

Conclusions: Children with migraine exhibit a delayed development of visual motion processing. This might be a useful supplementary biomarker in paediatric migraine.

White matter microstructural alterations in migraine: a diffusion-weighted MRI study

Migraine is a common and disabling neurological disease. The pathomechanism that underlies the disorder is not entirely understood, and reliable biomarkers are missing. In the current analysis we looked for microstructural alterations of the brain white matter in migraine patients by means of diffusion-weighted magnetic resonance imaging. The measurements were carried out with a novel approach based on fine-tuned nonlinear registration and nonparametric permutation test in an alignment-invariant tract representation (Tract-Based Spatial Statistics). We found reduced fractional anisotropy in the right frontal white matter cluster of migraine patients. In the same region we also found increased mean diffusivity and increased radial diffusivity. The probabilistic tractography showed connection of this cluster to other parts of the pain network (orbitofrontal cortex, insula, thalamus, dorsal midbrain). We speculate that these findings reflect maladaptive plastic changes or white matter disintegration.