Migraine: What Imaging Reveals

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.

Vulnerability of the Hippocampus to Insults: Links to Blood-Brain Barrier Dysfunction

The hippocampus is a critical brain substrate for learning and memory; events that harm the hippocampus can seriously impair mental and behavioral functioning. Hippocampal pathophysiologies have been identified as potential causes and effects of a remarkably diverse array of medical diseases, psychological disorders, and environmental sources of damage. It may be that the hippocampus is more vulnerable than other brain areas to insults that are related to these conditions. One purpose of this review is to assess the vulnerability of the hippocampus to the most prevalent types of insults in multiple biomedical domains (i.e., neuroactive pathogens, neurotoxins, neurological conditions, trauma, aging, neurodegenerative disease, acquired brain injury, mental health conditions, endocrine disorders, developmental disabilities, nutrition) and to evaluate whether these insults affect the hippocampus first and more prominently compared to other brain loci. A second purpose is to consider the role of hippocampal blood-brain barrier (BBB) breakdown in either causing or worsening the harmful effects of each insult. Recent research suggests that the hippocampal BBB is more fragile compared to other brain areas and may also be more prone to the disruption of the transport mechanisms that act to maintain the internal milieu. Moreover, a compromised BBB could be a factor that is common to many different types of insults. Our analysis indicates that the hippocampus is more vulnerable to insults compared to other parts of the brain, and that developing interventions that protect the hippocampal BBB may help to prevent or ameliorate the harmful effects of many insults on memory and cognition.

Cortical Sulcal Abnormalities Revealed by Sulcal Morphometry in Patients with Chronic and Episodic Migraine

Purpose

Previous studies have reported mixed results regarding the importance of cortical abnormalities in patients with migraines. However, cortical sulci, as a component of the cerebral cortex, have not been specifically investigated in migraine patients. Therefore, we aim to evaluate alterations in cortical sulcal morphology among patients with chronic migraine (CM), episodic migraine (EM), and healthy controls (HCs).

Patients and Methods

In this cross-sectional study, structural magnetic resonance images were acquired from 35 patients with CM, 35 with EM, and 35 HCs. Cortical sulci were identified and reconstructed using the BrainVisa 5.0.4 software. We focused on regions involved in pain processing in which abnormal cortical structure were identified in previous neuroimaging studies. Morphometric analysis was performed to calculate sulcal parameters including mean depth, cortical thickness, and opening width. Partial correlation analyses of clinical characteristics and sulcal parameters were performed for CM, EM and the combined migraine (CM + EM) groups.

Results

In comparison with HCs, both CM and EM groups showed increased opening width in bilateral insula. In comparison with HC and EM groups, CM patients showed increased cortical thickness in bilateral superior postcentral sulcus, bilateral median frontal sulcus and left superior parietal sulcus, as well as increased mean depth in the left anterior callosomarginal fissure and decreased mean depth in bilateral superior frontal sulcus and left median frontal sulcus. Migraine frequency and disease duration were both correlated with cortical thickness in bilateral superior postcentral sulcus.

Conclusion

Abnormal sulcal morphometry primarily affected areas associated with pain processing in patients with migraine, with CM exhibiting more extensive abnormalities in areas related to sensory and affective processing. These changes may contribute to understanding the pathology of EM and CM.

Dedicated neuroimaging analysis in children with primary headaches: prevalence of lesions and a comparison between patients with and without migraines

BACKGROUND

This study evaluated the prevalence and types of intracranial lesions through dedicated imaging analysis of primary headaches in children and compared them between patients with and without migraine.

METHODS

This study included 190 children diagnosed with primary headache who underwent neuroimaging, including brain computed tomography (CT), CT angiography (CTA), and brain magnetic resonance imaging (MRI). All patients with primary headaches was divided into two groups, namely, the migraine and non-migraine groups, on the basis of data from electronic medical records. Clinical characteristics and imaging findings were evaluated and compared between the two groups.

RESULTS

Patients with migraine were old and had a longer period from symptom onset to diagnosis. CT was normal in 71 of 95 patients, whereas 7 of 29 patients who underwent CTA had vascular lesions; the migraine group (n = 6/20, [30%]) had higher incidence of vascular lesions than the non-migraine group (n = 1/9, [11.1%]); however, there was no statistically significant difference (p = 0.382). Furthermore, 57.5% (61/106) of children showed normal brain MRI. The most common brain MRI finding was dilated perivascular space (n = 18, [16.8%]). Most perivascular spaces were located in the basal ganglia (n = 72, [75.8%]) and were in linear patterns (n = 58, [63.0%]). There was no statistically significant difference between the two groups.

CONCLUSION

A low prevalence of significant abnormalities was found in children with primary headaches. Dilated perivascular space was the most common finding in both groups on MRI. CTA showed more vascular lesions in the migraine group than in the non-migraine group. Therefore, further evaluations are needed to reveal the relationship between vascular lesions or dilated perivascular space and pediatric primary headaches.

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.

Longitudinal differences in iron deposition in periaqueductal gray matter and anterior cingulate cortex are associated with response to erenumab in migraine

OBJECTIVES

The objective of this longitudinal study was to determine whether brain iron accumulation, measured using magnetic resonance imaging magnetic transverse relaxation rates (T2*), is associated with response to erenumab for the treatment of migraine.

METHODS

Participants (n = 28) with migraine, diagnosed using international classification of headache disorders 3rd edition criteria, were eligible if they had six to 25 migraine days during a four-week headache diary run-in phase. Participants received two treatments with 140 mg erenumab, one immediately following the pre-treatment run-in phase and a second treatment four weeks later. T2* data were collected immediately following the pre-treatment phase, and at two weeks and eight weeks following the first erenumab treatment. Patients were classified as erenumab responders if their migraine-day frequency at five-to-eight weeks post-initial treatment was reduced by at least 50% compared to the pre-treatment run-in phase. A longitudinal Sandwich estimator approach was used to compare longitudinal group differences (responders vs non-responders) in T2* values, associated with iron accumulation. Group visit effects were calculated with a significance threshold of p = 0.005 and cluster forming threshold of 250 voxels. T2* values of 19 healthy controls were used for a reference. The average of each significant region was compared between groups and visits with Bonferroni corrections for multiple comparisons with significance defined as p < 0.05.

RESULTS

Pre- and post-treatment longitudinal imaging data were available from 28 participants with migraine for a total of 79 quantitative T2* images. Average subject age was 42 ± 13 years (25 female, three male). Of the 28 subjects studied, 53.6% were erenumab responders. Comparing longitudinal T2* between erenumab responders vs non-responders yielded two comparisons which survived the significance threshold of p < 0.05 after correction for multiple comparisons: the difference at eight weeks between the erenumab-responders and non-responders in the periaqueductal gray (mean ± standard error; responders 43 ± 1 ms vs non-responders 32.5 ± 1 ms, p = 0.002) and the anterior cingulate cortex (mean ± standard error; responders 50 ± 1 ms vs non-responders 40 ± 1 ms, p = 0.01).

CONCLUSIONS

Erenumab response is associated with higher T2* in the periaqueductal gray and anterior cingulate cortex, regions that participate in pain processing and modulation. T2* differences between erenumab responders vs non-responders, a measure of brain iron accumulation, are seen at eight weeks post-treatment. Less iron accumulation in the periaqueductal gray and anterior cingulate cortex might play a role in the therapeutic mechanisms of migraine reduction associated with erenumab.

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).

Management of Episodic Migraine with Neuromodulation: A Case Report

Migraine is a highly prevalent neurovascular disorder that affects approximately 15% of the global population. Migraine attacks are a complex cascade of neurologic events that lead to debilitating symptoms and are often associated with inhibitory behavior. The constellation of severe signs and symptoms during the ictal phase (headache attack) makes migraine the third most common cause of disability globally in both sexes under the age of 50. Misuse of pharmaceuticals, such as opiates, can lead to devastating outcomes and exacerbation of pain and headache attacks. A safe and well-tolerated non-pharmacological research approach is high-definition transcranial direct current stimulation over the M1.

Impaired Inter-Hemispheric Functional Connectivity during Resting State in Female Patients with Migraine

The application of voxel-mirrored homotopic connectivity (VMHC) analysis to study the central mechanism of migraine has been limited. Furthermore, little is known about inter-hemispheric functional connectivity (FC) alterations during resting state in female patients with migraine. This study aimed to investigate potential interictal VMHC impairments in migraine without aura (MwoA) patients and the relationship between connectivity alterations and clinical parameters. Resting-state functional magnetic resonance imaging data and clinical information were acquired from 43 female MwoA patients and 43 matched healthy controls. VMHC analysis was used to compare differences between these two groups, and brain regions showing significant differences were chosen as a mask to perform a seed-based FC group comparison. Subsequent correlation analysis was conducted to explore the relationship between abnormal inter-hemispheric FC and clinical data. Compared with healthy controls, female MwoA patients revealed significantly decreased VMHC in the bilateral cerebellum; cuneus; and lingual, middle occipital, precentral and postcentral gyri. Seed-based FC analysis indicated disrupted intrinsic connectivity in the cerebellum, and default mode, visual and sensorimotor network. These VMHC and FC abnormalities were negatively correlated with clinical indexes including duration of disease, migraine days and visual analogue scale. These inter-hemispheric FC impairments and correlations between abnormal VMHC and FC and clinical scores may improve our understanding of the central mechanism of female-specific migraine.

New insight into the neural mechanisms of migraine in adolescents: Relationships with sleep

OBJECTIVE

This case-control study examines if measures of subjective and objective (actigraphic) sleep difficulties mediate alterations in amygdalar connectivity in adolescents with migraine compared to healthy adolescents.

BACKGROUND

Adolescents with migraine have different functional connectivity of the amygdala compared to individuals without migraine. Sleep is often disturbed in adolescents with migraine, and could contribute to the alterations in functional connectivity.

METHODS

Twenty adolescents with migraine and 20 healthy controls were recruited from Cincinnati Children's Hospital. Participants completed surveys about their headaches and overall sleep quality, sleep hygiene, and perceived sleep difficulties (Insomnia Severity Scale [ISI]); completed wrist-worn actigraphy; and underwent a magnetic resonance imaging scan.

RESULTS

Adolescents with migraine differed from healthy controls only in perceived difficulty in sleep initiation and maintenance (ISI: 8.5 ± 4.7 and 4.5 ± 3.7 [mean ± standard deviation], -4.00 [95% confidence: -6.7 to -1.3], p = 0.005) and had greater functional connectivity between the amygdala and the posterior cingulate cortex, precuneus, dorsolateral prefrontal, sensorimotor, and the occipital cortexes. The differences in functional connectivity of the amygdala were not mediated by the subjective/objective sleep measures (ISI/wake minutes after sleep onset).

CONCLUSIONS

Adolescents with migraine have greater connectivity between the amygdala and areas involved in sensory, affective, and cognitive aspects of pain. These alterations may not be due to higher levels of sleep difficulties in adolescents with migraine, suggesting that both amygdala and sleep alterations may play an independent role in migraine pathophysiology. This advances the understanding of the mechanisms underlying pediatric migraine and can potentially advance migraine management.

Tracking tDCS induced grey matter changes in episodic migraine: a randomized controlled trial

BACKGROUND

Occipital transcranial direct current stimulation (tDCS) is an effective and safe treatment for migraine attack prevention. Structural brain alterations have been found in migraineurs in regions related to pain modulation and perception, including occipital areas. However, whether these structural alterations can be dynamically modulated through tDCS treatment is understudied.

OBJECTIVE

To track longitudinally grey matter volume changes in occipital areas in episodic migraineurs during and up to five months after occipital tDCS treatment in a single-blind, and sham-controlled study.

METHODS

24 episodic migraineurs were randomized to either receive verum or sham occipital tDCS treatment for 28 days. To investigate dynamic grey matter volume changes patients underwent structural MRI at baseline (prior to treatment), 1.5 months and 5.5 months (after completion of treatment). 31 healthy controls were scanned with the same MRI protocol. Morphometry measures assessed rate of changes over time and between groups by means of tensor-based morphometry.

RESULTS

Before treatment, migraineurs reported 5.6 monthly migraine days on average. A cross-sectional analysis revealed grey matter volume increases in the left lingual gyrus in migraineurs compared to controls. Four weeks of tDCS application led to a reduction of 1.9 migraine days/month and was paralleled by grey matter volume decreases in the left lingual gyrus in the treatment group; its extent overlapping with that seen at baseline.

CONCLUSION

This study shows that migraineurs have increased grey matter volume in the lingual gyrus, which can be modified by tDCS. Tracking structural plasticity in migraineurs provides a potential neuroimaging biomarker for treatment monitoring.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT03237754 . Registered 03 August 2017 - retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03237754 .

Altered Brain Structure in Chronic Visceral Pain: Specific Differences in Gray Matter Volume and Associations With Visceral Symptoms and Chronic Stress

Structural brain alterations in chronic pain conditions remain incompletely understood, especially in chronic visceral pain. Patients with chronic-inflammatory or functional bowel disorders experience recurring abdominal pain in concert with other gastrointestinal symptoms, such as altered bowel habits, which are often exacerbated by stress. Despite growing interest in the gut-brain axis and its underlying neural mechanisms in health and disease, abnormal brain morphology and possible associations with visceral symptom severity and chronic stress remain unclear. We accomplished parallelized whole-brain voxel-based morphometry analyses in two patient cohorts with chronic visceral pain, i.e., ulcerative colitis in remission and irritable bowel syndrome, and healthy individuals. In addition to analyzing changes in gray matter volume (GMV) in each patient cohort vs. age-matched healthy controls using analysis of covariance (ANCOVA), multiple regression analyses were conducted to assess correlations between GMV and symptom severity and chronic stress, respectively. ANCOVA revealed reduced GMV in frontal cortex and anterior insula in ulcerative colitis compared to healthy controls, suggesting alterations in the central autonomic and salience networks, which could however not be confirmed in supplemental analyses which rigorously accounted for group differences in the distribution of sex. In irritable bowel syndrome, more widespread differences from healthy controls were observed, comprising both decreased and increased GMV within the sensorimotor, central executive and default mode networks. Associations between visceral symptoms and GMV within frontal regions were altered in both patient groups, supporting a role of the central executive network across visceral pain conditions. Correlations with chronic stress, on the other hand, were only found for irritable bowel syndrome, encompassing numerous brain regions and networks. Together, these findings complement and expand existing brain imaging evidence in chronic visceral pain, supporting partly distinct alterations in brain morphology in patients with chronic-inflammatory and functional bowel disorders despite considerable overlap in symptoms and comorbidities. First evidence pointing to correlations with chronic stress in irritable bowel syndrome inspires future translational studies to elucidate the mechanisms underlying the interconnections of stress, visceral pain and neural mechanisms of the gut-brain axis.

Acupuncture Modulation Effect on Pain Processing Patterns in Patients With Migraine Without Aura

Introduction

In this retrospective study, resting-state functional connectivity (FC) in patients with migraine was analyzed to identify potential pathological pain processing patterns and compared them to those in healthy controls (HCs). The FC patterns in patients between pre- and post-acupuncture sessions were also analyzed to determine how acupuncture affects neurological activity and pain perception during the migraine interictal period.

Methods

In total, 52 patients with migraine without aura (MwoA) and 60 HCs were recruited. Patients with migraine were given acupuncture treatment sessions for 4 weeks. As a primary observation, functional magnetic resonance images were obtained at the beginning and end of the sessions. HCs received no treatment and underwent one functional magnetic resonance imaging (fMRI) scan after enrollment. After the fMRI data were preprocessed, a region of interest (ROI)-to-ROI analysis was performed with predefined ROIs related to pain processing regions.

Results

The first analysis showed significantly different FCs between patients with MwoA and HCs [false discovery rate corrected p-value (p-FDR) < 0.05]. The FCs were found to be mainly between the cingulate gyrus (CG) and the insular gyrus, the CG and the inferior parietal lobule (IPL), the CG and the superior frontal gyrus, and the middle frontal gyrus and the IPL. The second analysis indicated that acupuncture treatment partly restored the different FCs found in the first analysis (p-FDR < 0.05). Furthermore, subgroup analysis found different brain activity patterns in headache-intensity restored condition and headache-frequency restored condition. Lastly, the correlation analysis suggested a potential correlation between FCs and clinical symptoms (p < 0.05).

Conclusion

This study suggests that pain processing is abnormal in migraine, with significantly abnormal FCs in the frontal, parietal, and limbic regions. This finding could be a typical pathological feature of migraine. Acupuncture has been identified to relieve headache symptoms in two ways: it restores the pain processing function and regulates pain perception.

Altered trigeminothalamic spontaneous low-frequency oscillations in migraine without aura: a resting-state fMRI study

Background

Recent resting-state fMRI studies demonstrated functional dysconnectivity within the central pain matrix in migraineurs. This study aimed to investigate the spatial distribution and amplitude of low-frequency oscillations (LFOs) using fractional amplitude of low-frequency fluctuation (fALFF) analysis in migraine patients without aura, and to examine relationships between regional LFOs and clinical variables.

Methods

Resting-state fMRI data were obtained and preprocessed in 44 migraine patients without aura and 31 matched controls. fALFF was computed according to the original method, z-transformed for standardization, and compared between migraineurs and controls. Correlation analysis between regional fALFF and clinical variables was performed in migraineurs as well.

Results

Compared with controls, migraineurs had significant fALFF increases in bilateral ventral posteromedial (VPM) thalamus and brainstem encompassing rostral ventromedial medulla (RVM) and trigeminocervical complex (TCC). Regional fALFF values of bilateral VPM thalamus and brainstem positively correlated with disease duration, but not with migraine attack frequency or Migraine Disability Assessment Scale score.

Conclusions

We have provided evidence for abnormal LFOs in the brainstem including RVM/TCC and thalamic VPM nucleus in migraine without aura, implicating trigeminothalamic network oscillations in migraine pathophysiology. Our results suggest that enhanced LFO activity may underpin the interictal trigeminothalamic dysrhythmia that could contribute to the impairments of pain transmission and modulation in migraine. Given our finding of increasing fALFF in relation to increasing disease duration, the observed trigeminothalamic dysrhythmia may indicate either an inherent pathology leading to migraine headaches or a consequence of repeated attacks on the brain.

Early alterations of cortical thickness and gyrification in migraine without aura: a retrospective MRI study in pediatric patients

Background

Migraine is the most common neurological disease, with high social-economical burden. Although there is growing evidence of brain structural and functional abnormalities in patients with migraine, few studies have been conducted on children and no studies investigating cortical gyrification have been conducted on pediatric patients affected by migraine without aura.

Methods

Seventy-two pediatric patients affected by migraine without aura and eighty-two controls aged between 6 and 18 were retrospectively recruited with the following inclusion criteria: MRI exam showing no morphological or signal abnormalities, no systemic comorbidities, no abnormal neurological examination. Cortical thickness (CT) and local gyrification index (LGI) were obtained through a dedicated algorithm, consisting of a combination of voxel-based and surface-based morphometric techniques. The statistical analysis was performed separately on CT and LGI between: patients and controls; subgroups of controls and subgroups of patients.

Results

Patients showed a decreased LGI in the left superior parietal lobule and in the supramarginal gyrus, compared to controls. Female patients presented a decreased LGI in the right superior, middle and transverse temporal gyri, right postcentral gyrus and supramarginal gyrus compared to male patients. Compared to migraine patients younger than 12 years, the ≥ 12-year-old subjects showed a decreased CT in the superior and middle frontal gyri, pre- and post-central cortex, paracentral lobule, superior and transverse temporal gyri, supramarginal gyrus and posterior insula. Migraine patients experiencing nausea and/or vomiting during headache attacks presented an increased CT in the pars opercularis of the left inferior frontal gyrus.

Conclusions

Differences in CT and LGI in patients affected by migraine without aura may suggest the presence of congenital and acquired abnormalities in migraine and that migraine might represent a vast spectrum of different entities. In particular, ≥ 12-year-old pediatric patients showed a decreased CT in areas related to the executive function and nociceptive networks compared to younger patients, while female patients compared to males showed a decreased CT of the auditory cortex compared to males. Therefore, early and tailored therapies are paramount to obtain migraine control, prevent cerebral reduction of cortical thickness and preserve executive function and nociception networks to ensure a high quality of life.

Headache frequency associates with brain microstructure changes in patients with migraine without aura

Neuroimaging studies have implicated abnormal brain microstructure in episodic migraine (EM), but whether the pattern is altered during migraine chronification is not well known. Fifty-six patients with migraine without aura, including 39 EM patients and 17 chronic migraine (CM) patients, and 35 healthy controls (HCs) were enrolled. Voxel-based morphometry analysis was performed to assess gray matter (GM) volume differences among groups and their association with clinical feature was examined. Compared with the HC group, both migraine groups showed increased GM volume in the periaqueductal grey matter (PAG) and decreased GM volume in the anterior cingulate cortex (ACC). The left hippocampus/parahippocampal gyrus (PHG) volume of the HC group was smaller than that of the EM group, but was larger than that of the CM group. For the dorsolateral prefrontal cortex (dlPFC), the EM group showed the smallest GM volume while the CM group had the largest volume. Higher headache frequency was associated with greater GM volume in the PAG and dlPFC, but was associated with smaller GM volume in the ACC and hippocampus/PHG across all patients. GM volume changes in regions involved in pain generation and control are potential neural mechanism underlying migraine, and are associated with migraine types and headache frequency.

The Altered Functional Connectivity With Pain Features Integration and Interaction in Migraine Without Aura

Introduction

Migraine without aura (MwoA) is a primary type of migraine, a common disabling disorder, and a disabling neurological condition. The headache is a complex experience, a common form of pain, in which multiple sensory information dimensions are combined to provide a unified conscious event. Migraine ictal have unique neuroimage biomarkers, but the brain is also affected during the inter-ictal phase. According to the current studies, a hypothesis was constructed that the altered integration of pain spatial and intensity information impacts headache intensity in the inter-ictal period.

Methods

In this study, we applied theory-based region-to-region functional connectivity (FC) analyses to compare the differences in resting-state FC between MwoA participants and healthy controls with the pain integration hypothesis. After the correlation matrices between FC edges and clinical symptoms were constructed, the moderating effect and simple slope tests were investigated to explain whether and how the dysfunction of pain features discrimination affects the clinical symptoms.

Results

Functional connectivity analyses showed significantly decreased FC edges between the left dorsolateral superior frontal gyrus (SFGdor) and left insula, and an increased FC edge between the left SFGdor and bilateral angular gyrus. The correlation matrix showed no significant correlation between significantly altered FC edge and headache duration, frequency, Zung self-rating anxiety scale, and Zung self-rating depression scale. Only one significantly altered edge in the MwoA condition was significantly correlated with headache intensity. Moderating Module 1 and 2 manifested the moderator variable (altered rs-FC edge) moderated the link between the normal edges and headache intensity.

Conclusion

The pain features integration processes in migraineurs vary from HCs, related to the clinical symptoms during a migraine attack. Moreover, the clinical symptoms will be affected by one or more discrimination modules. And the spatial or intensity discrimination modules have a higher impact when combined with another module on clinical symptoms than the single module.

Giving Researchers a Headache - Sex and Gender Differences in Migraine

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

Enhanced mindfulness-based stress reduction in episodic migraine: a randomized clinical trial with magnetic resonance imaging outcomes

We aimed to evaluate the efficacy of an enhanced mindfulness-based stress reduction (MBSR+) vs stress management for headache (SMH). We performed a randomized, assessor-blind, clinical trial of 98 adults with episodic migraine recruited at a single academic center comparing MBSR+ (n = 50) with SMH (n = 48). MBSR+ and SMH were delivered weekly by group for 8 weeks, then biweekly for another 8 weeks. The primary clinical outcome was reduction in headache days from baseline to 20 weeks. Magnetic resonance imaging (MRI) outcomes included activity of left dorsolateral prefrontal cortex (DLPFC) and cognitive task network during cognitive challenge, resting state connectivity of right dorsal anterior insula to DLPFC and cognitive task network, and gray matter volume of DLPFC, dorsal anterior insula, and anterior midcingulate. Secondary outcomes were headache-related disability, pain severity, response to treatment, migraine days, and MRI whole-brain analyses. Reduction in headache days from baseline to 20 weeks was greater for MBSR+ (7.8 [95% CI, 6.9-8.8] to 4.6 [95% CI, 3.7-5.6]) than for SMH (7.7 [95% CI 6.7-8.7] to 6.0 [95% CI, 4.9-7.0]) (P = 0.04). Fifty-two percent of the MBSR+ group showed a response to treatment (50% reduction in headache days) compared with 23% in the SMH group (P = 0.004). Reduction in headache-related disability was greater for MBSR+ (59.6 [95% CI, 57.9-61.3] to 54.6 [95% CI, 52.9-56.4]) than SMH (59.6 [95% CI, 57.7-61.5] to 57.5 [95% CI, 55.5-59.4]) (P = 0.02). There were no differences in clinical outcomes at 52 weeks or MRI outcomes at 20 weeks, although changes related to cognitive networks with MBSR+ were observed. Enhanced mindfulness-based stress reduction is an effective treatment option for episodic migraine.

Individual differences of maladaptive brain changes in migraine and their relationship with differential effectiveness of treatments

Migraine is a difficult disorder to identify with regard to its pathophysiological mechanisms, and its treatment has been primarily difficult owing to interindividual differences. Substantial rates of nonresponsiveness to medications are common, making migraine treatment complicated. In this review, we systematically analyzed recent studies concerning neuroimaging findings regarding the neurophysiology of migraine. We linked the current imaging research with anecdotal evidence from interindividual factors such as duration and pain intensity of migraine, age, gender, hormonal interplay, and genetics. These factors suggested the use of nonpharmacological therapies such as transcranial magnetic stimulation, transcranial direct current stimulation, and placebo therapy for the treatment of migraine. Finally, we discussed how interindividual differences are related to such nondrug treatments.

Application of the Migraine Aura Complexity Score (MACS): Clinical and Neuroimaging Study

Background: Manifestations of typical migraine aura can be numerous. Investigation of its pathophysiological mechanisms can be challenging if a stratification of phenotypes is not performed. In this context, the Migraine Aura Complexity Score (MACS), recently developed, may help. Here we aimed to categorize migraine patients into homogenous groups using MACS and to compare those groups with respect to patients' characteristics and neuroimaging findings. Methods: Participants who have a migraine with aura (MwA) were interviewed after each attack in order to obtain the characteristics of migraine aura. Thereafter, we scored the complexity of their auras by MACS. The MACS was used to categorize patients into three groups: MwA-S (with simple aura), MwA-MC (with moderately complex aura), and MwA-C (with complex aura). The patient characteristics and estimated cortical thickness of regions of interest, which are potentially linked to the symptoms that develop during the aura, were used to compare these groups. Results: In total, 338 MwA attacks were recorded in analyzed groups. Scotoma was the most frequently reported symptom in the groups, followed by somatosensory aura in the MwA-C group and zig-zag lines in the MwA-MC and MwA-S groups. Patients in the MwA-C and MwA-MC groups had a thicker cortex in the left primary visual cortex with respect to MwA-S group. In addition, patients in the MwA-C group had a thicker cortex in several visual and somatosensory cortical regions relative to the MwA-S group. Conclusions: Our results show that the newly developed MACS can be used for the stratification of MwA patients, herewith allowing the better investigation of changes in migraineurs' brains.

Recent Advances in Pharmacotherapy for Migraine Prevention: From Pathophysiology to New Drugs

Migraine is a common and disabling neurological disorder, with a significant socioeconomic burden. Its pathophysiology involves abnormalities in complex neuronal networks, interacting at different levels of the central and peripheral nervous system, resulting in the constellation of symptoms characteristic of a migraine attack. Management of migraine is individualised and often necessitates the commencement of preventive medication. Recent advancements in the understanding of the neurobiology of migraine have begun to account for some parts of the symptomatology, which has led to the development of novel target-based therapies that may revolutionise how migraine is treated in the future. This review will explore recent advances in the understanding of migraine pathophysiology, and pharmacotherapeutic developments for migraine prevention, with particular emphasis on novel treatments targeted at the calcitonin gene-related peptide (CGRP) pathway.

Subcortical Volume Changes in Migraine with Aura

Background and Purpose

Various features of the cerebral cortex and white matter have been extensively investigated in migraine with aura (MwA), but the morphological characteristics of subcortical structures have been largely neglected. The aim of this study was to identify possible differences in subcortical structures between MwA patients and healthy subjects (HS), and also to determine the correlations between the characteristics of migraine aura and the volumes of subcortical structures.

Methods

Thirty-two MwA patients and 32 HS matched by sex and age were analyzed in this study. Regional subcortical brain volumes were automatically calculated using the FSL/FMRIB Image Registration and Segmentation Tool software (https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/Glossary). A general linear model analysis was used to investigate differences in the volume of subcortical structures between the MwA patients and HS. A partial correlation test was used to assess correlations between the volume of subcortical structures and characteristics of MwA.

Results

The volumes of the right globus pallidus, left globus pallidus, and left putamen were significantly smaller in MwA patients than in HS (mean±SD): 1,427±135 mm³ vs. 1,557±136 mm³ (p<0.001), 1,436±126 mm³ vs. 1,550±139 mm³ (p=0.001), and 4,235±437 mm³ vs. 4,522±412 mm³ (p=0.006), respectively. There were no significant relationships between subcortical structures and clinical parameters.

Conclusions

These findings suggest that both the globus pallidi and left putamen play significant roles in the pathophysiology of the MwA. Future studies should determine the cause-and-effect relationships, since these could not be discriminated in this study due to its cross-sectional design.

Imaging Post-Traumatic Headache

PURPOSE OF REVIEW

Headache is a frequent and debilitating symptom after mild traumatic brain injury, yet little is known about its pathophysiology and most effective treatments. The goal of this review is to summarize findings from imaging studies used during the clinical evaluation and research investigation of post-traumatic headache (PTH).

RECENT FINDINGS

There are no published recommendations or guidelines for when to acquire imaging studies of the head or neck in patients with PTH. Clinical acumen is required to determine if imaging is needed to assess for a secondary cause of headache which may have been precipitated or unmasked by the trauma. Several guidelines for when to image the patient with mild traumatic brain injury (mTBI) in the emergency setting consider headache among the deciding factors. In the research arena, imaging techniques including proton spectroscopy magnetic resonance imaging, diffusion tensor imaging, magnetic resonance morphometry, and functional neck x-rays have been employed with the goal of identifying diagnostic and prognostic factors for PTH and to help understand its underlying pathophysiologic mechanisms. Results indicate that changes in regional cortical thickness and damage to specific white matter tracts warrant further research. Future research should interrogate whether these imaging findings contribute to the classification and prognosis of PTH. Current research provides evidence that imaging findings associated with PTH may be distinct from those attributable to mTBI. A variety of imaging techniques have potential to further our understanding of the pathophysiologic processes underlying PTH as well as to provide diagnostic and prognostic indicators. However, considerable work must be undertaken for this to be realized.

Gray matter volume modifications in migraine

Objective

To explore cross-sectional and longitudinal gray matter (GM) volume changes in patients with migraine and their association with patients' clinical characteristics and disease activity.

Methods

Brain T2-weighted and 3-dimensional T1-weighted scans were acquired from 73 episodic migraineurs and 46 age- and sex-matched nonmigraine controls at baseline. Twenty-four migraineurs and 25 controls agreed to be reexamined after a mean follow-up of 4 years. Using a general linear model and SPM12, a whole-brain analysis was performed to assess GM volume modifications.

Results

At baseline, compared to controls, patients with migraine showed lower cerebellar GM volume and higher volume of regions of the frontotemporal lobes. At follow-up, migraineurs were significantly older than controls. Over the follow-up, migraineurs developed an increased volume of frontotemporoparietal regions, which was more prominent in patients with a higher baseline disease activity: long disease duration and high attack frequency. Migraineurs also developed decreased GM volume of visual areas, which was related to higher pain severity. Patients with an increased attack frequency at follow-up experienced both increased and decreased volume of nociceptive regions. In migraineurs, reduced GM volume of extrastriate visual areas during the follow-up was significantly correlated to baseline disease activity: shorter disease duration and lower attack frequency.

Conclusion

In this cohort, the migraine brain changes dynamically over time, and different pathophysiologic mechanisms can occur in response to patients' disease severity. The interaction between predisposing brain traits and experience-dependent responses might vary across different nociceptive and visual areas, thus leading to distinct patterns of longitudinal GM volume changes.

A critical evaluation of validity and utility of translational imaging in pain and analgesia: Utilizing functional imaging to enhance the process

Assessing clinical pain and metrics related to function or quality of life predominantly relies on patient reported subjective measures. These outcome measures are generally not applicable to the preclinical setting where early signs pointing to analgesic value of a therapy are sought, thus introducing difficulties in animal to human translation in pain research. Evaluating brain function in patients and respective animal model(s) has the potential to characterize mechanisms associated with pain or pain-related phenotypes and thereby provide a means of laboratory to clinic translation. This review summarizes the progress made towards understanding of brain function in clinical and preclinical pain states elucidated using an imaging approach as well as the current level of validity of translational pain imaging. We hypothesize that neuroimaging can describe the central representation of pain or pain phenotypes and yields a basis for the development and selection of clinically relevant animal assays. This approach may increase the probability of finding meaningful new analgesics that can help satisfy the significant unmet medical needs of patients.

An update on migraine: current understanding and future directions

Migraine is a common brain disorder with high disability rates which involves a series of abnormal neuronal networks, interacting at different levels of the central and peripheral nervous system. An increase in the interest around migraine pathophysiology has allowed researchers to unravel certain neurophysiological mechanisms and neurotransmitter involvement culminating in the recent development of novel therapies, which might substantially change the clinical approach to migraine patients. The present review will highlight the current aspects of migraine pathophysiology, covering an understanding of the complex workings of the migraine state and the brain regions responsible for them. We will further discuss the therapeutic agents which have appeared in the most recent years for migraine care, from calcitonin gene-related peptide (CGRP) receptor antagonists, gepants; through serotonin 5-HT1F receptor agonists, ditans, and CGRP or CGRP receptor monoclonal antibodies to invasive and non-invasive neuromodulation techniques.

Brain Changes in Responders vs. Non-Responders in Chronic Migraine: Markers of Disease Reversal

The aim of this study was to identify structural and functional brain changes that accompanied the transition from chronic (CM; ≥15 headache days/month) to episodic (EM; <15 headache days/month) migraine following prophylactic treatment with onabotulinumtoxinA (BoNT-A). Specifically, we examined whether CM patients responsive to prophylaxis (responders; n = 11), as evidenced by a reversal in disease status (defined by at least a 50% reduction in migraine frequency and <15 headache days/month), compared to CM patients whose migraine frequency remained unchanged (non-responders; n = 12), showed differences in cortical thickness using surface-based morphometry. We also investigated whether areas showing group differences in cortical thickness displayed altered resting-state functional connectivity (RS-FC) using seed-to-voxel analyses. Migraine characteristics measured across groups included disease duration, pain intensity and headache frequency. Patient reports of headache frequency over the 4 weeks prior to (pre-treatment) and following (post-treatment) prophylaxis were compared (post minus pre) and this measure served as the clinical endpoint that determined group assignment. All patients were scanned within 2 weeks of the post-treatment visit. Results revealed that responders showed significant cortical thickening in the right primary somatosensory cortex (SI) and anterior insula (aINS), and left superior temporal gyrus (STG) and pars opercularis (ParsOp) compared to non-responders. In addition, disease duration was negatively correlated with cortical thickness in fronto-parietal and temporo-occipital regions in responders but not non-responders, with the exception of the primary motor cortex (MI) that showed the opposite pattern; disease duration was positively associated with MI cortical thickness in responders versus non-responders. Our seed-based RS-FC analyses revealed anti-correlations between the SI seed and lateral occipital (LOC) and dorsomedial prefrontal cortices (DMPFC) in responders, whereas non-responders showed increased connectivity between the ParsOp seed and LOC. Overall, our findings revealed distinct morphometric and functional brain changes in CM patients that reverted to EM following prophylactic treatment compared to CM patients that showed no change in disease status. Elucidating the CNS changes involved in disease reversal may be critical to discovering interventions that prevent or slow the progression of CM. Such changes may aid in the evaluation of treatments as well as provide markers for disease “de-chronification”.