Migraine and structural changes in the brain: a systematic review and meta-analysis

Retinal neural tissue and vascular calibres in migraine: the Northern Finland Birth Cohort Eye Study

PURPOSE

To evaluate the possible effects of migraine on retinal nerve fibre layer (RNFL), ganglion cell-inner plexiform layer (GC-IPL), macular thickness and retinal arteriolar and venular diameters (CRAE, CRVE) in a population-based birth cohort.

METHODS

375 migraineurs and 1489 healthy controls were included in this cross-sectional cohort study. RNFL, GC-IPL and macular thickness parameters were measured by spectral domain optical coherence tomography (OCT), and vascular parameters were measured from fundus photographs. Migraine was determined by a questionnaire and specific features were selected as covariates (gender, smoking status, systolic blood pressure, refraction and diabetes).

RESULTS

There were no statistically significant differences between healthy controls and migraineurs in average RNFL (p = 0.123), macular (p = 0.488) or GC-IPL (p = 0.437) thickness. Migraine did not have a significant effect on any of the macular or GC-IPL subfields. For RNFL subfields, only temporal inferior was borderline significantly increased in migraineurs (p = 0.039) in adjusted results. No statistically significant differences were found between study groups on retinal vascular calibres CRAE (p = 0.879), CRVE (p = 0.145) or AVR (p = 0.259). GC-IPL thickness was found to be positively correlated with CRAE and CRVE in both study groups as GC-IPL thickness increased together with the increase in CRAE and CRVE (p-trend < 0.001 in both), and a similar trend was detected with central macular subfield thickness and systolic (p-trend < 0.001) and diastolic (p-trend = 0.010) blood pressure, but only in the control group.

CONCLUSION

There were no remarkable differences between migraineurs and healthy controls in retinal vascular or structural parameters in our study.

Bruxism, temporomandibular disorders, and headache-a narrative review of correlations and causalities

ABSTRACT

The co-occurrence of bruxism, temporomandibular disorders (TMDs), and headache is common in patients. However, there is conflicting evidence regarding whether this association is simply a result of their high prevalence or whether there are indeed causal relationships. This review provides an overview of the current state of research while taking into account the controversies surrounding research methods, particularly in definitions and diagnostic standards. Bruxism-defined as repetitive jaw muscle activity during sleep or wakefulness-is not a painful disorder but may-particularly in co-occurrence with TMD-worsen pre-existing headache. It seems important to differentiate between sleep and awake bruxism because of different impact on pathophysiological processes in different primary headache disorders such as migraine and tension-type headache. Temporomandibular disorder is a heterogenous entity with both myofascial and arthrogenous types of pain in addition to nonpainful disorders. Research suggests a correlation between TMD pain and migraine, as well as between awake bruxism and tension-type headache. However, psychosocial factors may act as confounders in these relationships. Determining causality is challenging because of the limited number of experimental and clinical studies conducted on this topic. The main finding is an apparent lack of consensus on the definition and assessment criteria for bruxism. Treatment wise, it is important to differentiate all 3 conditions because treatment of one condition may have an effect on the other 2 without proving causality. For future research, it is crucial to establish greater consistency and applicability in diagnostic procedures and definitions. In addition, more experimental and clinical studies investigating the question of causality are needed.

Association between vertebral artery dominance and basilar artery curvature in migraineurs: an anatomical magnetic resonance imaging study

BACKGROUND AND PURPOSES

Numerous studies demonstrate a link between cerebrovascular alterations and migraine pathogenesis. We investigated the association between migraine and vertebral artery dominance (VAD), basilar artery (BA) curvature, and elongation.

MATERIALS AND METHODS

This cross-sectional MRI study included 74 migraine patients and 74 control subjects aged between 18 and 55 years. Diameters of the intracranial part of the vertebral artery (VA) and BA, height of the BA bifurcation, and total lateral displacement of the BA were measured. In addition, we investigated the directional relationship between VAD and BA curvature.

RESULTS

There were no statistically significant differences between the groups regarding VA and BA diameters and total lateral displacement of the BA. The height of the BA bifurcation was found to be significantly higher in migraine patients compared to controls (p = 0.002). The left-side VAD was more frequent in migraine patients compared to control subjects (60.8% (45/74) vs 41.9% (31/74), p = 0.001). In migraine patients, particularly those with aura (MwA) patients, with left-side VAD, the rate of BA displacement to the right side is significantly higher than those with right-side VAD or non-VAD (p = 0.022). Also, we found that total lateral displacement of the BA is correlated with VA asymmetry in patients with MwA (r = 0.538, p = 0.007).

CONCLUSION

VAD and its opposite-directional relationship with the lateral displacement of the BA may be associated with migraine pathophysiology. Together with aging, this association may contribute to changes in the vertebrobasilar system (VBS) geometry which may result in increased risk for posterior circulation infarction (PCI) in migraineurs.

A retrospective review of sex differences of white matter hyperintensities in brain MRI of patients with migraine

OBJECTIVES

The primary objective of this study was to evaluate the prevalence of white matter hyperintensities (WMHs) in patients who experience migraine and compare findings between adult male and female patients. Specific symptoms and comorbidities also were analyzed to determine whether they were associated with WMH prevalence or the sex of patients with migraine. We hypothesized that females would have a higher prevalence of WMHs, experience more frequent and more severe migraine headaches, and be more likely to have certain comorbidities associated with migraine than males.

BACKGROUND

An increased prevalence of WMHs in patients with migraine has been proposed, although this relation is not well-supported by data from population-based MRI studies. The difference in brain morphology between males and females is of research interest, and females in the general population appear to have a higher prevalence of WMHs. Sex differences and various comorbidities in patients with migraine relative to the number of WMHs on brain imaging have not been fully investigated.

METHODS

This was a cross-sectional study of 177 patients aged 18 years and older with a diagnosis of migraine who were seen in the Lehigh Valley Fleming Neuroscience Institute's Headache Center between January 1, 2000, and January 1, 2017. Patients' baseline characteristics were extracted from electronic medical records, including demographics, review of systems documentation, and brain imaging from MRI. Variables including headache severity, frequency of head pain, insomnia, and comorbidities (anxiety, depression, diabetes, hyperlipidemia, hypertension, and neck pain) also were analyzed for associations with the presence of WMHs.

RESULTS

Females were found to have a significantly higher number of WMHs than males (median 3 [IQR: 0-7] vs. 0 [IQR: 0-3], p = 0.023). Patients with WMHs were significantly more likely than those without WMHs to have hypertension (39.8% of patients with WMHs vs. 20.3% without WMHs, p = 0.011), constipation (20.9% vs. 8.3%, p = 0.034), and sleep disorder (55.7% vs. 37.3%, p = 0.022). Females with migraine were significantly more likely to experience constipation than males (20.0% vs. 2.9%, p = 0.015). None of the migraine characteristics studied (frequency, severity, presence of aura) were different between sexes, nor were they significantly associated with the presence of WMHs.

CONCLUSION

This study suggests that females with migraine may be more likely to have WMHs and experience constipation than males with migraine. Migraine frequency and severity were not different between sexes, nor were they significantly associated with the presence of WMHs. The findings of this study do not support a specific etiology of WMH development in individuals with migraine that differs from findings in the general population. Further studies are warranted.

Silent brain infarct in migraine: Systematic review and meta-analysis

BACKGROUND

While migraine, particularly migraine with aura, is a recognized risk factor for ischemic stroke, the association of migraine with silent brain infarction is a matter of debate, as studies on this topic have yielded conflicting results.

METHODS

A systematic review of the literature was conducted of studies reporting migraine and silent brain infarction, assessed by magnetic resonance imaging, between January 1980 and April 2022, by consulting Medline and Embase databases. Studies with a control group were included in a meta-analysis of population-based studies. An exploratory meta-analysis of both population-based and clinical-based studies was further performed to test the association between migraine with aura and silent brain infarction.

RESULTS

A total of 2,408 articles were identified, among which 24 were included in the systematic review and 10 in the meta-analysis. The meta-analysis of population-based studies showed no association of migraine with silent brain infarction (odds ratio (OR)=1.32 [95% CI 0.92;1.90], P=0.13) and migraine with aura with silent brain infarction (OR=1.56 [0.74;3.30], P=0.24). However, in the exploratory meta-analysis of population-based and clinical-based studies, migraine with aura was significantly associated with silent brain infarction (OR=1.91 [1.02;3.59], P=0.04) and to silent cerebellar infarcts (OR=2.57 [1.01;6.56], P=0.05).

CONCLUSION

In this updated systematic review and meta-analysis of population-based studies, migraine and migraine with aura were not associated with silent brain infarction.

Cerebral microstructural alterations in Post-COVID-condition are related to cognitive impairment, olfactory dysfunction and fatigue

After contracting COVID-19, a substantial number of individuals develop a Post-COVID-Condition, marked by neurologic symptoms such as cognitive deficits, olfactory dysfunction, and fatigue. Despite this, biomarkers and pathophysiological understandings of this condition remain limited. Employing magnetic resonance imaging, we conduct a comparative analysis of cerebral microstructure among patients with Post-COVID-Condition, healthy controls, and individuals that contracted COVID-19 without long-term symptoms. We reveal widespread alterations in cerebral microstructure, attributed to a shift in volume from neuronal compartments to free fluid, associated with the severity of the initial infection. Correlating these alterations with cognition, olfaction, and fatigue unveils distinct affected networks, which are in close anatomical-functional relationship with the respective symptoms.

Migraine or any headaches and white matter hyperintensities and their progression in women and men

BACKGROUND

Cross-sectional and longitudinal studies have been conducted to investigate the association between migraine and any headache and white matter hyperintensities (WMH). However, studies are inconsistent regarding the strength of the association and its clinical significance. The aim of our study was to investigate the association between headache and its subtypes (migraine with aura (MigA+), migraine without aura (MigA-), non-migraine headache (nonMigHA)) and WMH and its course in the population-based 1000BRAINS study using state-of-the-art imaging techniques and migraine classification according to modified international classification of headache disorders.

METHODS

Data from 1062 participants (45% women, 60.9 ± 13.0 years) with ever or never headache (neverHA) and complete quantitative (WMH volume) and qualitative (Fazekas classification) WMH data at first imaging and after 3.7 ± 0.7 years (393 participants) were analyzed. The sex-specific association between headache and its subtypes and WMH volume and its change was evaluated by linear regression, between headache and its subtypes and Fazekas score high vs. low (2-3 vs. 0-1) by log-binomial regression, adjusted for confounders.

RESULTS

The lifetime prevalence of headache was 77.5% (10.5% MigA+, 26.9% MigA-, 40.1% nonMigHA). The median WMH volume was 4005 (IQR: 2454-6880) mm3 in women and 4812 (2842-8445) mm3 in men. Women with any headaches (all headache types combined) had a 1.23 [1.04; 1.45]-fold higher WMH volume than women who reported never having had a headache. There was no indication of higher Fazekas grading or more WMH progression in women with migraine or any headaches. Men with migraine or any headaches did not have more WMH or WMH progression compared to men without migraine or men who never had headache.

CONCLUSIONS

Our study demonstrated no increased occurrence or progression of WMH in participants with mgiraine. But, our results provide some evidence of greater WMH volume in women with headache of any type including migraine. The underlying pathomechanisms and the reasons why this was not shown in men are unclear and require further research.

Association between migraine and the risk of vascular dementia: A nationwide longitudinal study in South Korea

OBJECTIVE

We aimed to examine the potential association between migraine and vascular dementia (VaD) using a nationwide population database.

BACKGROUND

Migraine and VaD showed similar structural and functional changes in pathophysiology process and shared common risk factors, However, whether migraine prevalence increases VaD incidence remains controversial.

METHODS

This retrospective population-based cohort study used the medical records from the Korean National Health Insurance System database. Migraine (G43) was defined by using the Tenth Revision of the International Classification of Diseases code. More than two migraine diagnoses at least 3 months apart were defined as "chronic migraine". Cox proportional hazards model estimated hazard ratios (HRs) of VaD for group comparisons.

RESULTS

We included 212,836 patients with migraine and 5,863,348 individuals without migraine. During 10 years of follow-up, 3,914 (1.8%) and 60,258 (1.0%) patients with and without migraine, respectively, were newly diagnosed with VaD. After adjustment, patients with migraine showed a 1.21-fold higher risk of VaD than those without migraine (HR = 1.21; 95% confidence interval (CI): 1.17-1.25). Patients with chronic migraine showed a higher cumulative incidence of VaD than those with episodic migraine. The adjusted HR for the VaD incidence with migraine was higher in: (1) patients aged <65 years; (2) women; (3) patients without hypertension, diabetes, or atrial fibrillation; and (4) non-smokers.

CONCLUSION

Migraine is associated with an increased risk of VaD, particularly in chronic migraine patients. Incidence of VaD in the setting of migraine may have distinct pathophysiology from that of VaD with traditional cardiovascular risks.

Potential of focal cortical dysplasia in migraine pathogenesis

Focal cortical dysplasias are abnormalities of the cerebral cortex associated with an elevated risk of neurological disturbances. Cortical spreading depolarization/depression is a correlate of migraine aura/headache and a trigger of migraine pain mechanisms. However, cortical spreading depolarization/depression is associated with cortical structural changes, which can be classified as transient focal cortical dysplasias. Migraine is reported to be associated with changes in various brain structures, including malformations and lesions in the cortex. Such malformations may be related to focal cortical dysplasias, which may play a role in migraine pathogenesis. Results obtained so far suggest that focal cortical dysplasias may belong to the causes and consequences of migraine. Certain focal cortical dysplasias may lower the threshold of cortical excitability and facilitate the action of migraine triggers. Migraine prevalence in epileptic patients is higher than in the general population, and focal cortical dysplasias are an established element of epilepsy pathogenesis. In this narrative/hypothesis review, we present mainly information on cortical structural changes in migraine, but studies on structural alterations in deep white matter and other brain regions are also presented. We develop the hypothesis that focal cortical dysplasias may be causally associated with migraine and link pathogeneses of migraine and epilepsy.

Correlation between migraine and cerebral small vessel disease: A case-control study

BACKGROUND

Microcirculatory pathology is one of the pathophysiological theories of migraine, which may present as visually subclinical lesions. Image markers of cerebral small vessel disease (CSVD) have been investigated in elderly migraineurs. However, past studies looked at only part of image features, and the conclusions may have been hindered by confounding factors. The relationship between migraine and CSVD signs needs reliable demonstrations.

METHODS

We conducted a case-control study by recruiting episodic young migraineurs from a tertiary headache centre, with tension-type headache (TTH) and healthy controls. Distinct image features of microvascular damage and baseline characteristics across groups were assessed, and multivariate linear regression was performed to evaluate the risk factors for image abnormalities in migraineurs.

RESULTS

Forty-eight migraineurs, 32 TTHs and 49 healthy controls were included. The median age was 32 year-old. 58.7% of the participants were female. The Scheltens score and volume of white matter hyperintensities (WMHs) in migraineurs, and the number of Virchow-Robin spaces (VRSs) in both migraineurs and TTHs were different from those in normal controls. No lacunar infarct-like lesions (ILLs) or cerebral microbleeds (CMBs) were found. Age, education level (high level: β = -2.23, lobar WMHs), attack duration (long duration: β = 3.81, lobar WMHs) and attack frequency were independent risk factors for Scheltens score and volume of WMH in migraineurs. Migraine aura (β = -2.389), attack frequency and education level were correlated with the number of VRSs.

CONCLUSIONS

Migraine was associated with WMHs and VRSs. Aura, attack duration, attack frequency, age and education level were risk factors for image abnormalities of CVSD in migraineurs.

SIGNIFICANCE

This study provides a novel and comprehensive landscape of CSVD MRI features in young migraineurs, and it fills the blank of CMBs and VRSs which received less attention, with more persuasive, more reliable and stronger evidence of the association between CSVD and migraine. Our results also imply some new feature of TTH and the possible pathophysiology of the migraine course as well as new clues for the early management of migraine in terms of visual brain damage.

Genetics of migraine: complexity, implications, and potential clinical applications

Migraine is a common neurological disorder with large burden in terms of disability for individuals and costs for society. Accurate diagnosis and effective treatments remain priorities. Understanding the genetic factors that contribute to migraine risk and symptom manifestation could improve individual management. Migraine has a strong genetic basis that includes both monogenic and polygenic forms. Some distinct, rare, familial migraine subtypes are caused by pathogenic variants in genes involved in ion transport and neurotransmitter release, suggesting an underlying vulnerability of the excitatory-inhibitory balance in the brain, which might be exacerbated by disruption of homoeostasis and lead to migraine. For more prevalent migraine subtypes, genetic studies have identified many susceptibility loci, implicating genes involved in both neuronal and vascular pathways. Genetic factors can also reveal the nature of relationships between migraine and its associated biomarkers and comorbidities and could potentially be used to identify new therapeutic targets and predict treatment response.

Signatures of migraine aura in high-density-EEG

OBJECTIVE

Cortical spreading depolarization is highly conserved among the species. It is easily detectable in direct cortical surface recordings and has been recorded in the cortex of humans with severe neurological disease. It is considered the pathophysiological correlate of human migraine aura, but direct electrophysiological evidence is still missing. As signatures of cortical spreading depolarization have been recognized in scalp EEG, we investigated typical spontaneous migraine aura, using full band high-density EEG (HD-EEG).

METHODS

In this prospective study, patients with migraine with aura were investigated during spontaneous migraine aura and interictally. Time compressed HD-EEG were analyzed for the presence of cortical spreading depolarization characterized by (a) slow potential changes below 0.05 Hz, (b) suppression of faster activity from 0.5 Hz - 45 Hz (c) spreading of these changes to neighboring regions during the aura phase. Further, topographical changes in alpha-power spectral density (8-14 Hz) during aura were analyzed.

RESULTS

In total, 26 HD-EEGs were recorded in patients with migraine with aura, thereof 10 HD-EEGs during aura. Eight HD-EEGs were recorded in the same subject. During aura, no slow potentials were recorded, but alpha-power was significantly decreased in parieto-occipito-temporal location on the hemisphere contralateral to visual aura, lasting into the headache phase. Interictal alpha-power in patients with migraine with aura did not differ significantly from age- and sex-matched healthy controls.

CONCLUSIONS

Unequivocal signatures of spreading depolarization were not recorded with EEG on the intact scalp in migraine. The decrease in alpha-power contralateral to predominant visual symptoms is consistent with focal depression of spontaneous brain activity as a consequence of cortical spreading depolarization but is not specific thereof.

SIGNIFICANCE

Cortical spreading depolarization is relevant in migraine, other paroxysmal neurological disorders and neurointensive care.

The glymphatic system in migraine and other headaches

Glymphatic system is an emerging pathway of removing metabolic waste products and toxic solutes from the brain tissue. It is made of a network of perivascular spaces, filled in cerebrospinal and interstitial fluid, encompassing penetrating and pial vessels and communicating with the subarachnoid space. It is separated from vessels by the blood brain barrier and from brain tissue by the endfeet of the astrocytes rich in aquaporin 4, a membrane protein which controls the water flow along the perivascular space. Animal models and magnetic resonance (MR) studies allowed to characterize the glymphatic system function and determine how its impairment could lead to numerous neurological disorders (e.g. Alzheimer's disease, stroke, sleep disturbances, migraine, idiopathic normal pressure hydrocephalus). This review aims to summarize the role of the glymphatic system in the pathophysiology of migraine in order to provide new ways of approaching to this disease and to its therapy.

Modulation of temporal and occipital cortex by acupuncture in non-menstrual MWoA patients: a rest BOLD fMRI study

OBJECTIVE

To investigate the changes in amplitude of low-frequency fluctuation (ALFF) and degree centrality (DC) values before and after acupuncture in young women with non-menstrual migraine without aura (MWoA) through rest blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI).

METHODS

Patients with non-menstrual MWoA (Group 1, n = 50) and healthy controls (Group 2, n = 50) were recruited. fMRI was performed in Group 1 at 2 time points: before acupuncture (time point 1, TP1); and after the end of all acupuncture sessions (time point 2, TP2), and performed in Group 2 as a one-time scan. Patients in Group 1 were assessed with the Migraine Disability Assessment Questionnaire (MIDAS) and the Short-Form McGill Pain Questionnaire (SF-MPQ) at TP1 and TP2 after fMRI was performed. The ALFF and DC values were compared within Group 1 at two time points and between Group 1 and Group2. The correlation between ALFF and DC values with the statistical differences and the clinical scales scores were analyzed.

RESULTS

Brain activities increased in the left fusiform gyrus and right angular gyrus, left middle occipital gyrus, and bilateral prefrontal cortex and decreased in left inferior parietal lobule in Group 1, which had different ALFF values compared with Group 2 at TP1. The bilateral fusiform gyrus, bilateral inferior temporal gyrus and right middle temporal gyrus increased and right angular gyrus, right superior marginal gyrus, right inferior parietal lobule, right middle occipital gyrus, right superior frontal gyrus, right middle frontal gyrus, right anterior central gyrus, and right supplementary motor area decreased in activity in Group 1 had different DC values compared with Group 2 at TP1. ALFF and DC values of right inferior temporal gyrus, right fusiform gyrus and right middle temporal gyrus were decreased in Group1 at TP1 compared with TP2. ALFF values in the left middle occipital area were positively correlated with the pain degree at TP1 in Group1 (correlation coefficient r, r = 0.827, r = 0.343; P < 0.01, P = 0.015). The DC values of the right inferior temporal area were positively correlated with the pain degree at TP1 in Group 1 (r = 0.371; P = 0.008).

CONCLUSION

Spontaneous brain activity and network changes in young women with non-menstrual MwoA were altered by acupuncture. The right temporal area may be an important target for acupuncture modulated brain function in young women with non-menstrual MwoA.

Migraine-like headache in subjects with isolated Lambl's excrescences: a case series and literature review

AIM

Lambl's excrescences are mobile, thin, fibrinous connective tissue strands typically found on left-sided cardiac values. Migraine is positively associated with structural cardiac anomalies. However, it remains unclear whether Lambl's excrescences are associated with migraine.

METHODS

Retrospective review of 182 inpatients with Lambl's excrescences confirmed by transesophageal echocardiogram in Chinese PLA General Hospital since January 2010. Among them, those with isolated Lambl's excrescences presented with migraine-like headache were included. We collected information on the demographics and clinical profiles of all participants, and performed follow-up visits.

RESULTS

A total of 8 patients presented with migraine-like headache among 15 patients with isolated Lambl's excrescences. They included 2 men and 6 women, with an average age of 44.63 ± 12.24 years. Among these patients, 3 had visual aura, and 6 manifested infarct-like lesions on magnetic resonance imaging, of which 2 developed lesions after first visit. During follow-up, 4 patients suffering from intervention for Lambl's excrescences dramatically reduced headache recurrence compared to the other 4 patients only receiving migraine preventive medications.

CONCLUSIONS

This study supports the hypothesis that microemboli from isolated Lambl's excrescences could cause migraine-like headache. And intervention for Lambl's excrescences may be crucial for preventing headache recurrence.

Bibliometric Analysis of Research on Migraine-Stroke Association from 2013 to 2023

Background

Both migraine and stroke heavily burden individuals, health systems, and society. The migraine-stroke association is of concern and has been studied widely. Our objective is to explore and overview the current research status and emerging trends.

Materials and Methods

Studies on migraine-stroke association from January 2013 to May 2023 were retrieved and screened from the Web of Science Core Collection (WOSCC) database. Records fulfilling the selection criteria were downloaded and imported into CiteSpace for data mining and visualization.

Results

A total of 862 papers on migraine-stroke association were included. Annual publications grew slowly. The United States and European countries dominated research in this area. Harvard University published the largest number of articles, while the University of London was most active with other institutions. Ayata Cenk contributed the most articles, while KURTH T and NEUROLOGY were co-cited most. Research hotspots included migraine with aura, ischemic stroke, patent foramen ovale, cortical spreading depolarization, meta-analysis, cross-sectional study, and risk factors. Pathophysiology and small vessel disease represented research frontiers and emerging trends.

Conclusion

Our study scientifically outlines the migraine-stroke association over the past decade, presenting useful information.

Cortical spreading depolarization-induced constriction of penetrating arteries can cause watershed ischemia: A potential mechanism for white matter lesions

Periventricular white matter lesions (WMLs) are common MRI findings in migraine with aura (MA). Although hemodynamic disadvantages of vascular supply to this region create vulnerability, the pathophysiological mechanisms causing WMLs are unclear. We hypothesize that prolonged oligemia, a consequence of cortical spreading depolarization (CSD) underlying migraine aura, may lead to ischemia/hypoxia at hemodynamically vulnerable watershed zones fed by long penetrating arteries (PAs). For this, we subjected mice to KCl-triggered single or multiple CSDs. We found that post-CSD oligemia was significantly deeper at medial compared to lateral cortical areas, which induced ischemic/hypoxic changes at watershed areas between the MCA/ACA, PCA/anterior choroidal and at the tip of superficial and deep PAs, as detected by histological and MRI examination of brains 2-4 weeks after CSD. BALB-C mice, in which MCA occlusion causes large infarcts due to deficient collaterals, exhibited more profound CSD-induced oligemia and were more vulnerable compared to Swiss mice such that a single CSD was sufficient to induce ischemic lesions at the tip of PAs. In conclusion, CSD-induced prolonged oligemia has potential to cause ischemic/hypoxic injury at hemodynamically vulnerable brain areas, which may be one of the mechanisms underlying WMLs located at the tip of medullary arteries seen in MA patients.

Towards precision medicine in migraine: Recent therapeutic advances and potential biomarkers to understand heterogeneity and treatment response

After 35 years since the introduction of the International Classification of Headache Disorders (ICHD), we are living in the era of the second great revolution in migraine therapies. First, discoveries of triptans provided a breakthrough in acute migraine treatment utilizing bench-to-bedside research results on the role of serotonin in migraine. Next, the discovery of the role of neuropeptides, more specifically calcitonin gene-related peptide (CGRP) in migraine attack led to the development of anti-CGRP therapies that are effective both in acute and preventive treatment, and are also able to reduce migraine-related burden. Here, we reviewed the most recent clinical studies and real-world data on available migraine-specific medications, including triptans, ditants, gepants and anti-CGRP monoclonal antibodies. Novel drug targets, such as PACAP and amylins were also discussed. To address the main challenges of migraine therapy, the high heterogeneity of people with migraine, the prevalent presence of various comorbid disorders, and the insufficient medical care of migraine patients were covered. Promising novel approaches from the fields of omics, blood and saliva biomarker, imaging and provocation studies might bring solutions for these challenges with the potential to identify further drug targets, distinguish more homogeneous patient subgroups, contribute to more optimal drug selection strategies, and detect biomarkers in association with headache features or predicting treatment efficacy. In the future, the combined analysis of data of different biomarker modalities with machine learning algorithms may serve precision medicine in migraine treatment.

Migraine in older adults

Migraine is an evolving, and sometimes lifelong disorder. The prevalence of episodic migraine peaks among individuals aged in their late 30s, implying a tendency for the disorder to remit with increasing age thereafter, whereas chronic migraine is more likely to persist into later life. Diagnosis and treatment of migraine in older adults, defined as individuals aged 60 years or older, is rendered more complex by increasing probabilities of atypical clinical features and comorbidities, with patients' comorbidities sometimes limiting their therapeutic options. However, the changing clinical presentation of migraine over an individual's lifespan is not well characterised. The neurobiological basis of remission in older adults remains unclear, although vascular, neuronal, and hormonal changes are likely to be involved. Long-term longitudinal studies of individuals with migraine would be particularly informative, with the potential not only to suggest new research directions, but also to lead to the identification of novel therapeutic agents. Although several novel migraine medications are becoming available, their effectiveness, tolerability, and safety often remain uncertain in older adults, who have commonly been excluded from the evaluation of these agents in randomised controlled trials, or who constitute only a small proportion of study populations. There is a need to recognise these limitations in the available evidence, and the specific, and often unmet, clinical needs of older adults with migraine, not least because older adults constitute an increasing proportion of populations worldwide.

Association of white matter hyperintensities with migraine phenotypes and response to treatment

INTRODUCTION

White matter hyperintensities (WMHs) are frequently found in migraineurs. However, their clinical significance and correlation to different migraine phenotypes and treatment responses are not well defined. The study aimed to examine the association of WMHs with migraine clinical patterns and treatment response.

AIM OF WORK

We aimed to evaluate the association between WMHs and migraine phenotypes and explore the relationship of WMHs to treatment response.

METHODS

Our cross-sectional study formed of 500 migraineurs who sought treatment in Kafr el-sheik university hospital and underwent (3 T) MRI to evaluate WMHs. Different migraine phenotypes were compared between patients with and without WMHs. According to reduced headache pain intensity and frequency, these patients were divided into treatment responder and non-responder groups.

RESULTS

A total of 145 patients (29%) had WMHs. Patients with WMHs were significantly older, had a longer disease duration, and higher attack frequency. Patients who did not respond to acute and maintenance medications had a higher frequency of WMHs and high WMHs Scheltens score. Migraine with Aura and the presence of vomiting and dizziness were predictors for the development of WMHs.

CONCLUSION

WMHs are more common in migraine with aura. It is more frequent in migraine associated with vomiting and dizziness. WMHs increased with advancing age and more severe disease burden. Poorer response to acute and prophylactic medications was found in patients with WMHs.

Retina and microvascular alterations in migraine: a systemic review and meta-analysis

Objective

This study aimed to evaluate the retina and microvascular alterations with optical coherence tomography (OCT) or optical coherence tomography angiography (OCTA) in patients with migraine with aura (MA) and migraine without aura (MO).

Methods

PubMed, Embase, and Cochrane Library databases were searched to find relevant literature on patients with MA or MO using OCT/OCTA devices. The eligible data were analyzed by Stata Software (version 15.0).

Results

There were 16 studies identified, involving 379 eyes with MA, 583 eyes with MO, and 658 eyes of healthy controls. The thickness of the peripapillary retinal nerve fiber layer (pRNFL) of patients with MA decreased significantly in most regions. The foveal avascular zone (FAZ) area and perimeter in MA patients significantly enlarged, while the perfusion density (PD) in the macular deep capillary plexus (mDCP) significantly decreased in the whole image and its subregions except for the fovea, with the PD in radial peripapillary capillary (RPC) decreasing inside the disk. Patients with MO demonstrated a significantly decreased thickness of pRNFL in most regions, and the FAZ parameters were significantly enlarged. No statistical significance was observed in the retina and microvascular features of patients with MA and MO.

Conclusion

The eyes affected by MA and MO demonstrated significantly reduced thickness of pRNFL and enlarged FAZ. Patients with MA showed retinal microvascular impairments, including a decreased PD in mDCP. The OCT and OCTA could detect membrane morphology and circulation status in migraine and might provide the basis for the diagnosis and follow-up of patients with migraine.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, CRD42023397653.

Consensus statement for the management of incidentally found brain white matter hyperintensities in general medical practice

INTRODUCTION

There is a paradigm shift in our understanding of white matter hyperintensities (WMH) found on brain imaging. They were once thought to be a normal phenomenon of ageing and, therefore, warranted no further investigation. However, evidence now suggests these lesions are markers of poor brain and cardiovascular health, portending an increased risk of stroke, cognitive decline, depression and death. Nevertheless, no specific guidelines exist for the management of incidentally found WMH for general medical practitioners and other clinicians ordering brain magnetic resonance imaging scans for diverse clinical indications. Informed by a literature review and expert opinion gleaned from stroke neurologists, medical and imaging specialists, and general practitioners, we present our consensus statement to guide the management of incidentally found WMH in adults.

MAIN RECOMMENDATIONS

When incidental WMH are found on brain imaging: Perform a detailed history and examination to screen for neurological events. Investigate for potential undiagnosed or undertreated cardiovascular risk factors, especially hypertension and diabetes mellitus. Commence intensive and individualised cardiovascular risk management when risk factors are uncovered. Treat underlying risk factors via accepted guidelines but note that antiplatelet and anticoagulant medications should not be prescribed for incidental WMH in the absence of an alternative indication.

CHANGES TO MANAGEMENT AS A RESULT OF THIS CONSENSUS STATEMENT

A brain health opportunity. We consider the discovery of incidental WMH on brain imaging to represent an opportunity to investigate for common cardiovascular risk factors and to optimise brain health. This can be commenced and monitored by the general practitioner or physician without delay in waiting for an outpatient neurology review.

Migraine Aura-Catch Me If You Can with EEG and MRI-A Narrative Review

Roughly one-third of migraine patients suffer from migraine with aura, characterized by transient focal neurological symptoms or signs such as visual disturbance, sensory abnormalities, speech problems, or paresis in association with the headache attack. Migraine with aura is associated with an increased risk for stroke, epilepsy, and with anxiety disorder. Diagnosis of migraine with aura sometimes requires exclusion of secondary causes if neurological deficits present for the first time or are atypical. It was the aim of this review to summarize EEG an MRI findings during migraine aura in the context of pathophysiological concepts. This is a narrative review based on a systematic literature search. During visual auras, EEG showed no consistent abnormalities related to aura, although transient focal slowing in occipital regions has been observed in quantitative studies. In contrast, in familial hemiplegic migraine (FHM) and migraine with brain stem aura, significant EEG abnormalities have been described consistently, including slowing over the affected hemisphere or bilaterally or suppression of EEG activity. Epileptiform potentials in FHM are most likely attributable to associated epilepsy. The initial perfusion change during migraine aura is probably a short lasting hyperperfusion. Subsequently, perfusion MRI has consistently demonstrated cerebral hypoperfusion usually not restricted to one vascular territory, sometimes associated with vasoconstriction of peripheral arteries, particularly in pediatric patients, and rebound hyperperfusion in later phases. An emerging potential MRI signature of migraine aura is the appearance of dilated veins in susceptibility-weighted imaging, which may point towards the cortical regions related to aura symptoms ("index vein"). Conclusions: Cortical spreading depression (CSD) cannot be directly visualized but there are probable consequences thereof that can be captured Non-invasive detection of CSD is probably very challenging in migraine. Future perspectives will be elaborated based on the studies summarized.

The effects of physical exercise on structural, functional, and biochemical brain characteristics in individuals with chronic whiplash-associated disorder: A pilot randomized clinical trial

BACKGROUND

Exercise for people with whiplash associated disorder (WAD) induces hypoalgesic effects in some, but hyperalgesic effects in others. We investigated the exercise-induced neurobiological effects of aerobic and strengthening exercise in individuals with chronic WAD.

METHODS

Sixteen participants (8 WAD, 8 pain-free [CON]) were randomised to either aerobic or strengthening exercise. MRI for brain morphometry, functional MRI for brain connectivity, and magnetic resonance spectroscopy for brain biochemistry, were used at baseline and after the 8-week intervention.

RESULTS

There were no differences in brain changes between exercise groups in either the WAD or CON group, therefore aerobic and strengthening data were combined to optimise sample size. After the exercise intervention, the CON group demonstrated increased cortical thickness (left parahippocampus: mean difference = 0.04, 95% CI = 0.07-0.00, p = 0.032; and left lateral orbital frontal cortex: mean difference = 0.03, 95% CI = 0.00-0.06, p = 0.048). The WAD group demonstrated an increase in prefrontal cortex (right medial orbital frontal) volume (mean difference = 95.57, 95% CI = 2.30-192.84, p = 0.046). Functional changes from baseline to follow-up between the default mode network and the insula, cingulate cortex, temporal lobe, and somatosensory and motor cortices, were found in the CON group, but not in the WAD group. There were no changes post-exercise in brain biochemistry.

CONCLUSION

Aerobic and strengthening exercises did not exert differential effects on brain characteristics, however differences in structural and functional changes were found between WAD and CON groups. This suggests that an altered central pain modulatory response may be responsible for differential effects of exercise in individuals with chronic WAD.

White matter hyperintensities in migraine are not mediated by a dysfunction of the glymphatic system-A diffusion tensor imaging magnetic resonance imaging study

OBJECTIVE

We assessed whether brain magnetic resonance imaging (MRI) markers of glymphatic function are altered in patients with migraine and brain white matter hyperintensities (WMHs).

BACKGROUND

The glymphatic system is responsible for the outflow of waste products from the brain. An impaired glymphatic system has been associated with WMH; however, this impairment has not been shown in patients with migraine.

METHODS

The present cross-sectional study included consecutive patients with migraine from a single tertiary headache center. Glymphatic function was assessed by measuring the diffusion tensor imaging along the perivascular space (DTI-ALPS) technique, resulting in an index value. WMHs were assessed and quantified by using the Scheltens semi-quantitative score.

RESULTS

We included 147 patients (120 women [81.6%]) with a median (interquartile range [IQR]) age of 45 (36-50) years. In all, 74 (50.3%) patients had WMHs. The median (IQR) ALPS index was similar in patients with WMHs compared with those without, at 2.658 (2.332-3.199) versus 2.563 (2.222-3.050) (p = 0.344). The Scheltens score did not correlate with ALPS index (rho = 0.112, p = 0.268).

CONCLUSIONS

Our results suggest that the presence of WMHs is not associated with an impairment in the glymphatic system in patients with migraine. Although negative and worthy of further confirmation, our finding has implications for the understanding of the nature of WMH in patients with migraine.

Advanced brain MRI may help understand the link between migraine and multiple sclerosis

BACKGROUND

There is a clinical association between migraine and multiple sclerosis.

MAIN BODY

Migraine and MS patients share similar demographics, with the highest incidence among young, female and otherwise healthy patients. The same hormonal constellations/changes trigger disease exacerbation in both entities. Migraine prevalence is increased in MS patients, which is further enhanced by disease-modifying treatment. Clinical data show that onset of migraine typically starts years before the clinical diagnosis of MS, suggesting that there is either a unidirectional relationship with migraine predisposing to MS, and/or a "shared factor" underlying both conditions. Brain imaging studies show white matter lesions in both MS and migraine patients. Neuroinflammatory mechanisms likely play a key role, at least as a shared downstream pathway. In this review article, we provide an overview of the literature about 1) the clinical association between migraine and MS as well as 2) brain MRI studies that help us better understand the mechanistic relationship between both diseases with implications on their underlying pathophysiology.

CONCLUSION

Studies suggest a migraine history predisposes patients to develop MS. Advanced brain MR imaging may shed light on shared and distinct features, while helping us better understand mechanisms underlying both disease entities.

Sex and stress hormone dysregulation as clinical manifestations of hypothalamic function in migraine disorder: A meta-analysis

Migraine is a leading cause of disability in young adults. It occurs more frequently in females, often comorbidly with stress disorders, suggesting an association with hypothalamic sex and stress hormonal function and a likely interaction with autonomic nervous system activation. Thus, this study aimed to meta-analyse current literature pertaining to female and male sex hormones (estrogen, progesterone and testosterone concentration), hypothalamic-pituitary-adrenal axis (HPA axis) cortisol responses and heart rate variability (HRV) in migraineurs and controls aged 13-65 years. A systematic search of MEDLINE, Embase, PsycINFO, PubMed, CINAHL and Web of Science databases on 29/08/2022 identified 29 studies for meta-analysis (encompassing 719 migraineur and 592 control participants) that met inclusion and NHLBI risk of bias criteria. Results demonstrated that estrogen concentrations of female migraineurs were reduced (g = -.60, 95% CI [-.91, -.29], p < .001) in the luteal phase of the menstrual cycle, compared to controls. No differences were found in progesterone levels overall in female migraineurs, nor in testosterone levels in male migraineurs compared to controls. Further, early diurnal cortisol concentrations were elevated (g = .32, 95% CI [.00, .63], p = .036) in female and male migraineurs compared to controls, though no differences were found in HRV of female or male migraineurs compared to controls. These findings of dysregulation of estrogen in females and cortisol dysregulation in female and male migraineurs indicate perturbed hypothalamic function and highlight the association of migraine with stress and the need for further rigorous investigation of hypothalamic neuroendocrine functions in migraineurs of both sexes.

Assessing volumetric brain differences in migraine and depression patients: a UK Biobank study

BACKGROUND

Migraine and depression are two of the most common and debilitating conditions. From a clinical perspective, they are mostly prevalent in women and manifest a partial overlapping symptomatology. Despite the high level of comorbidity, previous studies hardly investigated possible common patterns in brain volumetric differences compared to healthy subjects. Therefore, the current study investigates and compares the volumetric difference patterns in sub-cortical regions between participants with migraine or depression in comparison to healthy controls.

METHODS

The study included data from 43 930 participants of the large UK Biobank cohort. Using official ICD10 diagnosis, we selected 712 participants with migraine, 1 853 with depression and 23 942 healthy controls. We estimated mean volumetric difference between the groups for the different sub-cortical brain regions using generalized linear regression models, conditioning the model within the levels of BMI, age, sex, ethnical background, diastolic blood pressure, current tobacco smoking, alcohol intake frequency, Assessment Centre, Indices of Multiple Deprivation, comorbidities and total brain volume.

RESULTS

We detected larger overall volume of the caudate (mean difference: 66, 95% CI [-3, 135]) and of the thalamus (mean difference: 103 mm³, 95% CI [-2, 208]) in migraineurs than healthy controls. We also observed that individuals with depression appear to have also larger overall (mean difference: 47 mm³, 95% CI [-7, 100]) and gray matter (mean difference: 49 mm³, 95% CI [2, 95]) putamen volumes than healthy controls, as well as larger amygdala volume (mean difference: 17 mm³, 95% CI [-7, 40]).

CONCLUSION

Migraineurs manifested larger overall volumes at the level of the nucleus caudate and of the thalamus, which might imply abnormal pain modulation and increased migraine susceptibility. Larger amygdala and putamen volumes in participants with depression than controls might be due to increased neuronal activity in these regions.

Diffusion tensor imaging in the courtroom: Distinction between scientific specificity and legally admissible evidence

Interest and uptake of science and medicine peer-reviewed literature by readers outside of a paper’s topical subject, field or even discipline is ever-expanding. While the application of knowledge from one field or discipline to others can stimulate innovative solutions to problems facing modern society, it is also fraught with danger for misuse. In the practice of law in the United States, academic papers are submitted to the courts as evidence in personal injury litigation from both the plaintiff (complainant) and defendant. Such transcendence of an academic publication over disciplinary boundaries is immediately met with the challenge of application by a group that inherently lacks in-depth knowledge on the scientific method, the practice of evidence-based medicine, or the publication process as a structured and internationally synthesized process involving peer review and guided by ethical standards and norms. A modern-day example of this is the ongoing conflict between the sensitivity of diffusion tensor imaging (DTI) and the legal standards for admissibility of evidence in litigation cases of mild traumatic brain injury (mTBI). In this review, we amalgamate the peer-reviewed research on DTI in mTBI with the court’s rationale underlying decisions to admit or exclude evidence of DTI abnormalities to support claims of brain injury. We found that the papers which are critical of the use of DTI in the courtroom reflect a primary misunderstanding about how diagnostic biomarkers differ legally from relevant and admissible evidence. The clinical use of DTI to identify white matter abnormalities in the brain at the chronic stage is a valid methodology both clinically as well as forensically, contributes data that may or may not corroborate the existence of white matter damage, and should be admitted into evidence in personal injury trials if supported by a clinician. We also delve into an aspect of science publication and peer review that can be manipulated by scientists and clinicians to publish an opinion piece and misrepresent it as an unbiased, evidence-based, systematic research article in court cases, the decisions of which establish precedence for future cases and have implications on future legislation that will impact the lives of every citizen and erode the integrity of science and medicine practitioners.

Do Mean Platelet Volume and Platelet Distribution Width Have An Association with White Matter Hyperintensities in Migraine Patients?

Objective

Increased prevalence of white matter hyperintensities (WMH) is reported in migraine patients; however, the pathophysiology and the progression of these lesions are not definitely clear. Mean platelet volume (MPV) and platelet distribution width (PDW) are easily obtained markers for platelet activity. The aim of this study is to evaluate the relationship between the presence of WMH and MPV and PDW in patients with migraine in order to determine the role of platelet activity in the pathophysiology of WMH.

Methods

Patients who were admitted to the neurology outpatient clinics of Baskent University Hospital from January 2011 to December 2015 with migraine and between 18 and 55 years of age were evaluated retrospectively. The blood samples were taken and total blood count parameters including MPV and PDW were analyzed. Brain magnetic resonance images were evaluated.

Results

Totally, 218 patients were evaluated in this study. Forty-eight (22.0%) patients had WMH in the brain magnetic resonance imaging. In patients with WMH, the median of age was higher than the patients without WMH and the difference was statistically significant (P < 0.05). There was no statistically significant difference between MPV, PDW values, and the presence of WMH.

Conclusions

There are multiple theories suggested for the mechanism of WMH, but the major cause and pathophysiology are still undetermined. Our data suggested that increased platelet activity is insufficient by itself to explain the pathophysiology of WMH in migraine patients and to improve the knowledge on this issue further large longitudinal studies should be performed.

Migrainous infarction: A serious complication of a common condition

ABSTRACT

Migrainous infarction is a rare neurologic condition that stems from an ordinary migraine with aura, and can cause ischemic stroke in young women. The pathophysiology of migrainous infarction is not entirely understood. An aura that is similar to previous auras but lasts longer than 60 minutes, along with evidence of acute ischemia on MRI, are diagnostic of migrainous infarction. Treatment aimed at minimizing migraine with aura is the most important preventive measure clinicians can take to help patients avoid this complication of migraine.

Corneal confocal microscopy identifies corneal nerve fiber loss in patients with migraine

BACKGROUND/HYPOTHESIS

Migraine affects >1 billion people but its pathophysiology remains poorly understood. Alterations in the trigeminovascular system play an important role. We have compared corneal nerve morphology in patients with migraine to healthy controls.

METHODS

Sixty patients with episodic (n = 32) or chronic (n = 28) migraine and 20 age-matched healthy control subjects were studied cross-sectionally. Their migraine characteristics and signs and symptoms of dry eyes were assessed. Manual and automated quantification of corneal nerves was undertaken by corneal confocal microscopy.

RESULTS

In patients with migraine compared to controls, manual corneal nerve fiber density (P < 0.001), branch density (P = 0.015) and length (P < 0.001); and automated corneal nerve fiber density (P < 0.001), branch density (P < 0.001), length (P < 0.001), total branch density (P < 0.001), nerve fiber area (P < 0.001), nerve fiber width (P = 0.045) and fractal dimension (P < 0.001) were lower. Automated corneal nerve fiber density was higher in patients with episodic migraine and aura (P = 0.010); and fractal dimension (P = 0.029) was lower in patients with more headache days in the last three months. Automated corneal nerve fiber density predicted a significant amount of the observed variance in pain intensity (adjusted r² = 0.14, partial r = -0.37, P = 0.004) in patients with migraine.

CONCLUSIONS

Corneal confocal microscopy reveals corneal nerve loss in patients with migraine. It may serve as an objective imaging biomarker of neurodegeneration in migraine.

Whole-brain functional gradients reveal cortical and subcortical alterations in patients with episodic migraine

Migraine is a type of headache with multiple neurological symptoms. Prior neuroimaging studies in patients with migraine based on functional magnetic resonance imaging have found regional as well as network-level alterations in brain function. Here, we expand on prior studies by establishing whole-brain functional connectivity patterns in patients with migraine using dimensionality reduction techniques. We studied functional brain connectivity in 50 patients with episodic migraine and sex- and age-matched healthy controls. Using dimensionality reduction techniques that project high-dimensional functional connectivity onto low-dimensional representations (i.e., eigenvectors), we found significant between-group differences in the eigenvectors between patients with migraine and healthy controls, particularly in the sensory/motor and limbic cortices. Furthermore, we assessed between-group differences in subcortical connectivity with subcortical weighted manifolds defined by subcortico-cortical connectivity multiplied by cortical eigenvectors and revealed significant alterations in the amygdala. Finally, leveraging supervised machine learning, we moderately predicted headache frequency using cortical and subcortical functional connectivity features, again indicating that sensory and limbic regions play a particularly important role in predicting migraine frequency. Our study confirmed that migraine is a hierarchical disease of the brain that shows alterations along the sensory-limbic axis, and therefore, the functional connectivity in these areas could be a useful marker to investigate migraine symptomatology.

White Matter Lesions Identified by Magnetic Resonance in Women with Migraine: A Volumetric Analysis and Clinical Correlations

BACKGROUND

Repeated migraine attacks and aura could independently cause structural changes in the central nervous system. Our research aims to study the correlation of migraine type, attack frequency, and other clinical variables with the presence, volume and localization of white matter lesions (WML), in a controlled study.

METHODS

Sixty volunteers from a tertiary headache center were selected and divided equally into four groups: episodic migraine without aura (MoA), episodic migraine with aura (MA), chronic migraine (CM) and controls (CG). Voxel-based morphometry techniques were used to analyze WML.

RESULTS

There were no differences in WML variables between groups. There was a positive correlation between age and the number and total volume of WMLs, which persisted in the comparison categorized by size and brain lobe. Disease duration was positively correlated with the number and total volume of WML, and when controlled by age, the correlation maintained significance only for the insular lobe. Aura frequency was associated with frontal and temporal lobe WMLs. There was no statistically significant correlation between WML and other clinical variables.

CONCLUSION

Migraine overall is not a risk factor for WML. Aura frequency is, however, associated with temporal WML. Disease duration, in adjusted analyses that account for age, is associated with insular WML.

Central Mechanism of Acupuncture Treatment in Patients with Migraine: Study Protocol for Randomized Controlled Neuroimaging Trial

Purpose

Acupuncture has been recognized as an effective and safe alternative therapy for migraine, but its central mechanism has not yet been adequately explained. Meanwhile, research into the clinical efficacy and central mechanism of true acupuncture (TA) and sham acupuncture (SA) is lacking. It is necessary to investigate whether TA has better efficacy than SA, and how they achieve different effects. This study aims to evaluate the efficacy of TA and SA, observe the brain response caused by TA and SA, and further investigate the central nervous mechanism of TA and SA treatment for patients with migraine.

Patients and Methods

This is a randomized controlled neuroimaging trial combining acupuncture treatment with functional magnetic resonance imaging, with patients and outcome assessors blinded. A total of 60 patients with migraine will be randomly allocated to receive 12 sessions of either TA or SA treatments (three sessions per week for 4 weeks), and 30 healthy participants will be recruited as the healthy control (HC) group. Outcome assessment and neuroimaging will be conducted before and after the entire intervention. A headache diary and questionnaires of life quality and psychological properties will be used to evaluate clinical efficacy. Multimodal magnetic resonance imagining data analysis will be used to investigate the central mechanism of TA or SA in treating migraine. Pearson's correlation analysis will be used to reveal the relationship between the brain response and clinical improvements.

Conclusion

The results of this study will reveal the brain response to TA and SA in patients with migraine and contribute to further expanding the knowledge of their central mechanism.

Study Registration

This trial has been approved by the ethics committee of Dongzhimen Hospital affiliated to Beijing University of Chinese Medicine (DZMEC-KY-2020-38) and registered in the Chinese Clinical Trial Registry (registration number ChiCTR2000033995).

What imaging has revealed about migraine and chronic migraine

Although migraine pathophysiology is not yet entirely understood, it is now established that migraine should be viewed as a complex neurological disease, which involves the interplay of different brain networks and the release of signaling molecules, instead of a pure vascular disorder. The field of migraine research has also progressed significantly due to the advancement of brain imaging techniques. Numerous studies have investigated the relation between migraine pathophysiology and cerebral hemodynamic changes, showing that vascular changes are neither necessary nor sufficient to cause the migraine pain. Abnormal function and structure of key cortical, subcortical, and brainstem regions involved in multisensory, including pain, processing have been shown to occur in migraine patients during both an acute attack and the interictal phase. Whether brain imaging alterations represent a predisposing trait or are the consequence of the recurrence of headache attacks is still a matter of debate. It is highly likely that brain functional and structural alterations observed in migraine patients derive from the interaction between predisposing brain traits and experience-dependent responses. Neuroimaging studies have also enriched our knowledge of the mechanisms responsible for migraine chronification and have shed light on the mechanisms of actions of acute and preventive migraine treatments.

Structural brain changes in patients with persistent headache after COVID-19 resolution

Headache is among the most frequently reported symptoms after resolution of COVID-19. We assessed structural brain changes using T1- and diffusion-weighted MRI processed data from 167 subjects: 40 patients who recovered from COVID-19 but suffered from persistent headache without prior history of headache (COV), 41 healthy controls, 43 patients with episodic migraine and 43 patients with chronic migraine. To evaluate gray matter and white matter changes, morphometry parameters and diffusion tensor imaging-based measures were employed, respectively. COV patients showed significant lower cortical gray matter volume and cortical thickness than healthy subjects (p < 0.05, false discovery rate corrected) in the inferior frontal and the fusiform cortex. Lower fractional anisotropy and higher radial diffusivity (p < 0.05, family-wise error corrected) were observed in COV patients compared to controls, mainly in the corpus callosum and left hemisphere. COV patients showed higher cortical volume and thickness than migraine patients in the cingulate and frontal gyri, paracentral lobule and superior temporal sulcus, lower volume in subcortical regions and lower curvature in the precuneus and cuneus. Lower diffusion metric values in COV patients compared to migraine were identified prominently in the right hemisphere. COV patients present diverse changes in the white matter and gray matter structure. White matter changes seem to be associated with impairment of fiber bundles. Besides, the gray matter changes and other white matter modifications such as axonal integrity loss seemed subtle and less pronounced than those detected in migraine, showing that persistent headache after COVID-19 resolution could be an intermediate state between normality and migraine.

Evaluating migraine with typical aura with neuroimaging

Objective

To provide an up-to-date narrative literature review of imaging in migraine with typical aura, as a means to understand better migraine subtypes and aura biology.

Background

Characterizing subtypes of migraine with typical aura and appreciating possible biological differences between migraine with and without aura, are important to understanding the neurobiology of aura and trying to advance personalized therapeutics in this area through imaging biomarkers. One means of doing this over recent years has been the use of increasingly advanced neuroimaging techniques.

Methods

We conducted a literature review of neuroimaging studies in migraine with aura, using a PubMed search for terms 'imaging migraine', 'aura imaging', 'migraine with aura imaging', 'migraine functional imaging' and 'migraine structural imaging'. We collated the findings of the main studies, excluding small case reports and series with n < 6, and have summarized these and their implications for better understanding of aura mechanisms.

Results

Aura is likely mediated by widespread brain dysfunction in areas involving, but not limited to, visual cortex, somatosensory and insular cortex, and thalamus. Higher brain excitability in response to sensory stimulation and altered resting-state functional connectivity in migraine sufferers with aura could have a genetic component. Pure visual aura compared to visual aura with other sensory or speech symptoms as well, may involve different functional reorganization of brain networks and additional mitochondrial dysfunction mediating more aura symptoms.

Conclusion

There is a suggestion of at least some distinct neurobiological differences between migraine with and without aura, despite the shared phenotypic similarity in headache and other migraine-associated symptoms. It is clear from the vast majority of aura phenotypes being visual that there is a particular predisposition of the occipital cortex to aura mechanisms. Why this is the case, along with the relationships between cortical spreading depression and headache, and the reasons why aura does not consistently present in affected individuals, are all important research questions for the future.

Prevalence and clinical characteristics of white matter hyperintensities in Migraine: A meta-analysis

BACKGROUND

Current evidences show an increased risk of white matter hyperintensities (WMHs) in migraineurs compared to age-matched controls. However, WMHs prevalence and the associations between WMHs and clinical characteristics in migraineurs have not been systematically evaluated using a meta-analytical approach. This study explored the pooled prevalence of WMHs and the associations of WMHs with the clinical characteristics in patients with migraine.

METHODS

A systematic review and meta-analysis of observational studies reporting the occurrence and clinical characteristics of patients with WMHs attributed to migraine was performed. We searched the PubMed, Web of Science, and Embase databases. Random-effects models were used to calculate the pooled prevalence rate, odds ratio (OR), or mean difference (MD) with corresponding 95% confidence intervals (CIs).

RESULTS

Thirty eligible studies were identified including 3,502 migraineurs aged 37.2 (mean) years. The pooled WMHs prevalence was 44 %, 45 %, and 38 % in migraine, migraine with aura, and migraine without aura groups, respectively. In migraineurs with WMHs, the frontal lobe and subcortical white matter were the most susceptible area. Compared with non-migraine controls, patients with migraine had increased odds for WMHs (OR 4.32, 95 % CI = 2.56-7.28, I² = 67 %). According to reported univariable results from included studies, pooled analysis showed that clinical characteristics including age, presence of aura, disease duration, hypertension, diabetes mellitus and right-to-left shunt were associated with the presence of WMHs. Migraine pain and aura characteristics were not related to WMHs.

CONCLUSIONS

These data suggest that WMHs are common in migraine, especially in those who are older or have aura, hypertension, diabetes mellitus, or right-to-left shunt. A better understanding of the WMHs attributed to migraine is needed in future studies.

The association between migraine and dementia - a national register-based matched cohort study

OBJECTIVES

Migraine and dementia, two major public health challenges, are associated, but more knowledge is needed to understand their relationship. Objectives of this study were to investigate 1) the association between non-self-reported measures of migraine and dementia, and whether dementia was associated with 2) migraine without aura (MO) and with aura (MA) in combination with migraine medication use, and 3) migraine severity operationalized as the number of migraine prescriptions.

STUDY DESIGN

Matched cohort study.

METHODS

National register data were obtained from individuals born between 1934 and 1958. Migraine cases (aged 25-58 years) were identified by migraine diagnoses and redeemed migraine medication. Migraine cases were matched with non-cases (N = 340,850) and date of diagnosis or medication redemption was defined as index year. Dementia was identified by dementia diagnoses and redeemed dementia medication.

RESULTS

We observed a 1.46 (95% CI: 1.26-1.69) times higher dementia rate in individuals with a migraine diagnosis and a 0.86 (95% CI: 0.76-0.97) times lower rate when using migraine medication. We found the highest dementia rate among individuals with MA, who also used migraine medication (HR = 2.23; 95% CI: 1.19-4.17), and the lowest rate among individuals with MO, who also used medication (HR = 1.25; 95% CI: 0.75-2.10). The number of migraine medication prescriptions was not associated with dementia.

CONCLUSIONS

Being registered with a migraine diagnosis was associated with a higher dementia rate, while use of prescribed migraine medication was not. The differences in the dementia rate among migraine cases identified via diagnoses versus medications warrants further investigation.

Multiple sclerosis and migraine: Links, management and implications

Multiple sclerosis (MS) is a chronic inflammatory disease leading to multifocal neuronal demyelination and axonal damage in the central nervous system (CNS). MS symptoms vary widely but typically do not include headaches. A large spectrum of headaches manifestations was reported as comorbidities in MS and results in additional disability. Migraine, tension-type headache and cluster headache are the most frequently reported primary headache syndromes in patients with MS (pwMS). Secondary causes of headache should be excluded (cerebral vein thrombosis, CNS or systemic infection, cervical and/or cranial trauma, headaches associated with psychiatric disorders, medication overuse headache, etc.) in this particular population. A careful medical history and general and neurological examinations and sometimes further investigations may be needed to rule out secondary headache syndromes. In pwMS, the headache could be an adverse effect of the disease-modifying therapies or a complication of pain medication overuse prescribed to relieve other causes of pain related to MS (neuropathic pain, mechanical pain, pain associated with spasticity, etc.). Migraine-type headache occurs in pwMS more frequently than in the general population. It can precede the disease onset, be associated with relapses, or appear during the MS course. A predominance of brainstem inflammatory lesions is described on magnetic resonance imaging (MRI) in MS patients with migraine. The relationship between both conditions remains unclear. Migraine and MS occur in the same demographic groups with similar background factors, including gender, hormonal status, and psychological features (anxiety, depression, stress). An early diagnosis and adequate treatment of migraine in MS patients are important to improve their quality of life. In this review, we focus on the relationship between MS and Migraine, discuss the differential diagnoses of migraine in pwMS, and describe its management in this particular context.

Migraine and its relation to other risk factors in patients with acute ischemic stroke and acute coronary syndrome

Background

Migraine has been recently studied as a risk factor for ischemic stroke (IS) and a possible link to a broader range of ischemic vascular disorders including angina and myocardial infarction is suggested.

Objectives

to study migraine and its relation to other risk factors in patients with acute IS and acute coronary syndrome (ACS).

Patients and methods

We studied 200 patients, 114 patients had acute IS and 86 patients with ACS, in addition to 850 control participants. All patients were subjected to detailed clinical and laboratory evaluation; including evaluation of traditional risk factors. All stroke patients were subjected to CT scan. Diagnosis of acute coronary syndrome was established clinically by ECG and cardiac specific enzymes. Migraine was diagnosed according to the international headache society and assessment of migraine severity was measured by the Migraine Disability Assessment (MIDAS) questionnaire.

Results

In patients with ischemic stroke, Risk Ratios (RR) of migraine was 3.3 for all migrainous patients, higher for migraine with aura (MA). In the cardiovascular group, it was 2.75 and again higher in MA. A positive correlation between migraine severity and both stroke severity and cardiac affection severity was found though non-significant in the cardiovascular group. There was no significant difference in hospital outcome in migrainous patients in both groups.

Conclusions

Patients with migraine have higher risk than non-migrainous patients for both cerebrovascular and coronary vascular diseases. Risk is stronger in MA in both conditions. Considering migraine in risk stratification of cerebrovascular and cardiovascular diseases is recommended.

Migraine Pharmacological Treatment and Cognitive Impairment: Risks and Benefits

Migraine is a common neurological disorder impairing the quality of life of patients. The condition requires, as an acute or prophylactic line of intervention, the frequent use of drugs acting on the central nervous system (CNS). The long-term impact of these medications on cognition and neurodegeneration has never been consistently assessed. The paper reviews pharmacological migraine treatments and discusses their biological and clinical effects on the CNS. The different anti-migraine drugs show distinct profiles concerning neurodegeneration and the risk of cognitive deficits. These features should be carefully evaluated when prescribing a pharmacological treatment as many migraineurs are of scholar or working age and their performances may be affected by drug misuse. Thus, a reconsideration of therapy guidelines is warranted. Furthermore, since conflicting results have emerged in the relationship between migraine and dementia, future studies must consider present and past pharmacological regimens as potential confounding factors.

Increased risk of all-cause, Alzheimer's, and vascular dementia in adults with migraine in Korea: a population-based cohort study

BACKGROUND

Studies investigating the association between migraine and dementia have reported inconsistent findings. This study aimed to evaluate whether patients with migraine have an increased risk of dementia compared to individuals without migraine.

METHODS

We obtained data from the 2002-2019 Korean National Health Insurance Health Screening Cohort. Non-migraine controls were selected using a 1:1 risk-set matching with a time-dependent propensity score. The main outcome was the development of all-cause dementia, and the secondary outcome was the development of each cause of dementia (Alzheimer's, vascular, mixed or other specified, and unspecified dementia). The incidence rate of dementia was calculated using Poisson regression, and the association between migraine and dementia was evaluated using Cox proportional hazards regression.

RESULTS

Among 88,390 participants, 66.1% were female, and the mean baseline age was 55.3 ± 9.4 years. During the study period, dementia cases were identified in 4,800 of the 44,195 patients with migraine and 3,757 of the 44,915 matched controls. The incidence rate of dementia was 139.6 (95% confidence interval [CI], 135.7-143.5) and 107.7 (95% CI, 104.3-111.1) cases per 10,000 person-years in patients with migraine and matched controls, respectively. Patients with migraine had a 1.30 (hazard ratio [HR], 1.30; 95% CI, 1.25-1.35), 1.29 (HR, 1.29; 95% CI, 1.23-1.35), 1.35 (HR, 1.35; 95% CI, 1.19-1.54), 1.36 (HR, 1.36; 95% CI, 1.00-1.83), and 1.30 (HR, 1.30; 95% CI, 1.17-1.45) times higher risk of developing all-cause dementia, Alzheimer's dementia, vascular dementia, mixed or other specified dementias, and unspecified dementia than their matched controls, respectively.

CONCLUSION

Our results suggest that migraine is associated with an increased risk of subsequent dementia. Further research is warranted to confirm these findings and to reveal the underlying mechanisms.

Primary headaches increase the risk of dementias: An 8-year nationwide cohort study

Background

Headache, a highly prevalent neurological disorder, has consistently been linked with an elevated risk of dementia. However, most studies are focused on the relationship with migraine in limited age groups. Therefore, the objective of this research was to look at the link between various type of headaches and dementias based on longitudinal population-based data.

Methods and results

Participants diagnosed with headache from 2002 to 2005 were selected and major covariates were collected. The diagnoses of Alzheimer’s disease, vascular dementia, and other dementias were observed from 2006 until 2013. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of dementias according to headache type were calculated by Cox proportional hazards regression. A number of 470,652 participants were observed for a mean of 7.6 years (standard deviation: 1.2), for approximately 3.6 million person-years. Both tension type headache (TTH) and migraine elevated the risk of all-cause dementias (TTH, aHR 1.18, 95% CI 1.13–2.24; migraine, aHR 1.18, 95% CI 1.13–2.24). Headaches had a greater influence in females and non-smokers as a risk factor of dementias. Patients with migraine who consumed alcohol had a higher risk of dementia, however this was not true with TTH patients. Among participants without comorbidities, TTH patients were more susceptible to dementia than migraine patients. Headache patients had a higher proportion of females regardless of headache type and approximately 1.5 times more individuals had three or more comorbidities compared to those without headache.

Conclusions

Headache could be an independent predictor for subsequent dementia risk. Future studies should focus on clarifying pathogenic pathways and possible dementia-related preventive measures in headache populations.

An Overview of Systematic Reviews of Chinese Herbal Medicine in the Treatment of Migraines

Background: In the past, systematic reviews (SRs) and meta-analyses (MAs) have been used to assess the efficacy of Chinese herbal medicine (CHM) in the treatment of migraines. However, robust conclusions have not yet been determined because of variations in the methodological and evidence quality of these SRs/MAs.

Objectives: We aimed to assess the methodological and reporting quality of SRs/MAs and evaluate the available evidence of the efficacy of CHM treatment of migraines.

Methods: We searched eight electronic databases from inception until 10 January 2022, without language restrictions. Two researchers were independently responsible for study screening and data extraction. The methodological and reporting quality of SRs/MAs were assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2 and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). The evidence quality of included SRs/MAs was evaluated by Grading of Recommendations Assessment, Development and Evaluation (GRADE). In addition, a descriptive analysis of the included SRs/MAs was included.

Results: Sixteen SRs/MAs, including 69 outcomes, were finally included in this overview. Data synthesis of the included SRs/MAs outcomes showed that CHM plus Western medicine (WM) was beneficial in the improvement of migraines. In comparison, there was conflicting evidence for the effectiveness of CHM used alone. CHM was better than WM in improving responder rate and acute medication usage and was superior to placebo in improving migraine days, responder rate, and migraine duration. However, there was insufficient evidence to verify the effectiveness of CHM for migraine treatment regarding pain severity and migraine frequency. All the included SRs/MAs showed extremely low methodological and reporting quality. The results of the GRADE system indicated that the quality of most of the pooled evidence was very low.

Conclusions: CHM may be beneficial in improving migraines and can be used as a complementary therapy. However, we should treat the conclusions of the evaluated SRs/MAs cautiously because of the low quality of evidence. Future SRs/MAs should focus on improving methodological and reporting quality. High-quality randomized controlled trials (RCTs) are needed to provide strong evidence for the efficacy of CHM treatment of migraines.

Cerebral Hemodynamics, Right-to-Left Shunt and White Matter Hyperintensities in Patients with Migraine with Aura, Young Stroke Patients and Controls

Background: Migraine with aura (MA) patients present an increased risk of cerebrovascular events. However, whether these patients present an increased white matter hyperintensities (WMHs) load compared to the general population is still under debate. Our study aimed to evaluate the relationship between cerebral hemodynamics, right-to-left shunt (RLS) and WMHs in MA patients, young patients with cryptogenic stroke or motor transient ischemic attack (TIA) and controls. Methods: We enrolled 30 MA patients, 20 young (<60 years) patients with cryptogenic stroke/motor TIA, and 10 controls. All the subjects underwent a transcranial Doppler bubble test to detect RLS and cerebral hemodynamics assessed by the breath holding index (BHI) for the middle (MCA) and posterior (PCA) cerebral arteries. Vascular risk factors were collected. The WMHs load on FLAIR MRI sequences was quantitatively assessed. Results: The stroke/TIA patients presented a higher prevalence of RLS (100%) compared with the other groups (p < 0.001). The MA patients presented a higher BHI compared with the other groups in the PCA (p = 0.010) and higher RLS prevalence (60%) than controls (30%) (p < 0.001). The WMHs load did not differ across groups. BHI and RLS were not correlated to the WMHs load in the groups. Conclusions: A preserved or more reactive cerebral hemodynamics and the presence of a RLS are likely not involved in the genesis of WMHs in MA patients. A higher BHI may counteract the risk related to their higher prevalence of RLS. These results need to be confirmed by further studies to be able to effectively identify the protective role of cerebral hemodynamics in the increased RLS frequency in MA patients.

The Characteristics of White Matter Hyperintensities in Patients With Migraine

Background

The presence of white matter hyperintensities (WMHs) in migraine is well-documented, but the location of WMH in patients with migraine is insufficiently researched. This study assessed WMH in patients with migraine using a modified version of the Scheltens visual rating scale, a semiquantitative scale for categorizing WMH in periventricular, lobar, basal ganglia, and infratentorial regions.

Methods

In total, 263 patients with migraine (31 men and232 women) enrolled in the American Registry for Migraine Research (ARMR) from Mayo Clinic Arizona and who had clinical brain magnetic resonance imaging (MRI) were included in this study. Those with imaging evidence for gross anatomical abnormalities other than WMHs were excluded. A board-certified neuroradiologist identified WMHs on axial T2 and fluid-attenuated inversion recovery (FLAIR) sequences. WMHs were characterized via manual inspection and categorized according to the scale's criteria.

Results

Results showed that 95 patients (36.1%, mean age: 41.8 years) had no WMHs on axial T2 and FLAIR imaging and 168 patients (63.9%, mean age: 51.4 year) had WMHs. Of those with WMHs, 94.1% (n = 158) had lobar hyperintensities (frontal: 148/158, 93.7%; parietal: 57/158, 36.1%; temporal: 35/158, 22.1%; and occipital: 9/158, 5.7%), 13/168, 7.7% had basal ganglia WMHs, 49/168, 29.1% had periventricular WMHs, and 17/168, 10.1% had infratentorial WMHs. In addition, 101/168 patients (60.1%) had bilateral WMHs and 67/168 (39.9%) had unilateral WMHs (34 right hemisphere/33 left hemisphere).

Discussion

Among ARMR participants who were enrolled by Mayo Clinic Arizona and who had clinical brain MRIs, nearly two-thirds had WMHs. The WMHs were the most common in the frontal lobes. Describing the features of WMHs in those with migraine, and comparing them with WMHs attributable to other etiologies, might be useful for developing classifiers that differentiate between migraine-specific WMH and other causes of WMH.

Migraine and the risk of dementia: a meta-analysis and systematic review

OBJECTIVES

To conduct a comprehensive systematic review and meta-analysis to explore the correlation between migraine and the risk of dementia.

METHODS

The PubMed, EMBASE, and Cochrane library databases were searched systematically. We selected cohort studies (prospective and retrospective) and case-control studies that reported migraine in patients with dementia, including vascular dementia. The pooled effects were analyzed to evaluate relative risk with 95% confidence intervals.

RESULTS

In total, nine studies (two case-control and seven cohort studies) including 291,549 individuals were identified. These studies indicated that people with migraine (relative risk = 1.33; 95% confidence interval: 1.16-1.53) have an increased risk of all-cause dementia. Additionally, the pooled results of four studies showed that migraine is associated with an increased risk of vascular dementia (relative risk = 1.85; 95% confidence interval: 1.22-2.81; P = 0.004).

CONCLUSIONS

Data from observational studies suggest that migraine may be a risk factor for dementia, particularly vascular dementia. More studies are warranted to explore the association between migraine and dementia and the potential common pathophysiological mechanisms.