Migraine-like headache from an infarction in the periaqueductal gray area of the midbrain

Overexpression of BDNF in the ventrolateral periaqueductal gray regulates the behavior of epilepsy-migraine comorbid rats

OBJECTIVE

To investigate the effects of brain-derived neurotrophic factor (BDNF) overexpression in the ventrolateral periaqueductal gray (vlPAG) on behavioral changes in epilepsy-migraine comorbid rats.

METHOD

We used an adeno-associated virus (AAV)-mediated vector to supplement BDNF in the vlPAG area prior to the establishment of a pilocarpine-nitroglycerin (Pilo-NTG) combination-induced comorbid model of epilepsy and migraine. Seizure- and migraine-related behaviors were analyzed. Cell loss and apoptosis in vlPAG were detected through hematoxylin-eosin (HE) and TUNEL staining. Immunofluorescence staining analyses were employed to detect expressions of BDNF and its receptor, tyrosine kinase B (TrkB), in vlPAG. Immunohistochemical staining was conducted to detect expressions of c-Fos and calcitonin gene-related peptide (CGRP) in the trigeminal nucleus caudalis (TNC) and trigeminal ganglion (TG).

RESULTS

Comparing to control group, AAV-BDNF injected comorbid group showed lower pain sensitivity, scratching head, and spontaneous seizures accompanied by the downregulation of c-Fos labeling neurons and CGRP immunoreactivity in the TNC and TG. However, these changes were still significantly higher in the comorbid group than those in both epilepsy and migraine groups under the same intervention.

CONCLUSION

These data demonstrated that supplying BDNF to vlPAG may protect structural and functional abnormalities in vlPAG and provide an antiepileptic and analgesic therapy.

Symptomatic migraine: A systematic review to establish a clinically important diagnostic entity

OBJECTIVE

To determine if a clinical presentation indistinguishable from migraine can occur due to an underlying condition or pathology, that is, "symptomatic migraine."

BACKGROUND

It is currently not clear whether migraine truly can be caused by an underlying condition or pathology. Characterization of the etiology and clinical features of possible symptomatic migraine is of significant clinical importance and further may help elucidate the pathophysiology of migraine.

METHODS

We devised operational diagnostic criteria for "symptomatic migraine" and "possible symptomatic migraine" requiring strong evidence for a causal relation between underlying cause and migraine symptoms adhering strictly to diagnostic criteria. PubMed was searched for case reports of symptomatic migraine from inception to March 2020. Only articles published in English or German were included. No restrictions were placed on study design. Relevant references in the articles were also included. Papers were systematically reviewed by two independent reviewers for detailed clinical features of migraine as well as the proposed underlying conditions and the effects of treatment of these conditions.

RESULTS

Our search retrieved 1726 items. After screening, 109 papers comprising 504 cases were reviewed in detail. Eleven patients with migraine with aura (MWA) fulfilled our working criteria for symptomatic migraine, and 39 patients fulfilled our criteria for possible symptomatic migraine. The most common etiologies of symptomatic migraine were arteriovenous malformations, carotid stenosis, dissection or aneurysm, brain infarctions, meningioma, and various intra-axial tumors.

CONCLUSIONS

Symptomatic MWA, indistinguishable from idiopathic MWA, may occur due to cortical lesions or microembolization. We found no clear evidence supporting the existence of symptomatic migraine without aura although we did identify possible cases. Our findings are limited by the available literature, and we suggest that prospective studies are needed.

Decreased Resting-State Functional Connectivity of Periaqueductal Gray in Temporal Lobe Epilepsy Comorbid With Migraine

Objective: Patients with temporal lobe epilepsy (TLE) are at high risk for having a comorbid condition of migraine, and these two common diseases are proposed to have some shared pathophysiological mechanisms. Our recent study indicated the dysfunction of periaqueductal gray (PAG), a key pain-modulating structure, contributes to the development of pain hypersensitivity and epileptogenesis in epilepsy. This study is to investigate the functional connectivity of PAG network in epilepsy comorbid with migraine.

Methods: Thirty-two patients with TLE, including 16 epilepsy patients without migraine (EwoM) and 16 epilepsy patients with comorbid migraine (EwM), and 14 matched healthy controls (HCs) were recruited and underwent resting functional magnetic resonance imaging (fMRI) scans to measure the resting-state functional connectivity (RsFC) of PAG network. The frequency and severity of migraine attacks were assessed using the Migraine Disability Assessment Questionnaire (MIDAS) and Visual Analog Scale/Score (VAS). In animal experiments, FluoroGold (FG), a retrograde tracing agent, was injected into PPN and its fluorescence detected in vlPAG to trace the neuronal projection from vlPAG to PPN. FG traced neuron number was used to evaluate the neural transmission activity of vlPAG-PPN pathway. The data were processed and analyzed using DPARSF and SPSS17.0 software. Based on the RsFC finding, the excitatory transmission of PAG and the associated brain structure was studied via retrograde tracing in combination with immunohistochemical labeling of excitatory neurons.

Results: Compared to HCs group, the RsFC between PAG and the left pedunculopontine nucleus (PPN), between PAG and the corpus callosum (CC), was decreased both in EwoM and EwM group, while the RsFC between PAG and the right PPN was increased only in EwoM group but not in EwM group. Compared to EwoM group, the RsFC between PAG and the right PPN was decreased in EwM group. Furthermore, the RsFC between PAG and PPN was negatively correlated with the frequency and severity of migraine attacks. In animal study, a seizure stimulation induced excitatory transmission from PAG to PPN was decreased in rats with chronic epilepsy as compared to that in normal control rats.

Conclusion: The comorbidity of epilepsy and migraine is associated with the decreased RsFC between PAG and PPN.

Case Report: Migraine-Like Headache With Visual Aura Initiated by Endovascular Coiling Treatment for a Posterior Cerebral Artery Aneurysm

Cervical, anterior, and middle cerebral artery aneurysm is a causative factor for migraine, and endovascular treatment usually improves migraine headache. Posterior cerebral artery (PCA) aneurysm is a rare condition, and its association with migraine is very rarely reported. In addition, endovascular coiling treatment causing migraine-like headache has never been reported. Here, we describe a newly developed migraine-like headache with visual aura after endovascular coiling treatment for PCA aneurysm in a 31-year-old female patient. One month after the endovascular therapy, the patient stopped using the antiplatelet agents clopidogrel and aspirin and presented with an episodic headache attack twice a month with typical migraine features, including visual aura, right-sided temporal throbbing pain accompanied with nausea, vomiting, and photophobia. The recurrence of migraine-like headache with visual aura was terminated by clopidogrel administration. The generation of the migraine-like headache with visual aura is probably associated with microemboli due to endovascular coiling. This case supports the hypothesis that migraine with aura can be associated with microemboli of variant origins.

Ventrolateral Periaqueductal Gray Matter Neurochemical Lesion Facilitates Epileptogenesis and Enhances Pain Sensitivity in Epileptic Rats

The ventrolateral periaqueductal gray matter (vlPAG) plays a critical role in the pathogenesis of migraine and few studies have shown that vlPAG might be involved in the pathophysiology of epilepsy. But its roles in epileptogenesis and comorbid relationship between migraine and epilepsy have never been reported. In this study, the impairments of vlPAG neuronal network during spontaneous recurrent seizure (SRS) development after status epilepticus (SE) were investigated, and the pain sensitivity as well as the SRS investigated after neurochemical lesion to vlPAG to determine the role of vlPAG in epileptogenesis and in migraine comorbidity with epilepsy. Neuronal loss and alterations of excitatory and inhibitory neural transmission within vlPAG accompanied the development of epileptogenesis induced by SE. On the other hand, neurochemical lesion to vlPAG enhanced frequency and duration of spontaneous seizure event and frequency of epileptiform inter-ictal spike discharges in electroencephalography (EEG), but decreased pain threshold in epileptic rats. This indicates an involvement of the pain regulating structure, vlPAG, in the pathogenesis of epilepsy. This may imply that vlPAG network alterations could be a possible underlying mechanism of the interactive comorbid relationship between epilepsy and migraine.

Magnetic Resonance Image Texture Analysis of the Periaqueductal Gray Matter in Episodic Migraine Patients without T2-Visible Lesions

Objective

The periaqueductal gray matter (PAG), a small midbrain structure, presents dysfunction in migraine. However, the precise neurological mechanism is still not well understood. Herein, the aim of this study was to investigate the texture characteristics of altered PAG in episodic migraine (EM) patients based on high resolution brain structural magnetic resonance (MR) images.

Materials and Methods

The brain structural MR images were obtained from 18 normal controls (NC), 18 EM patients and 16 chronic migraine (CM) patients using a 3T MR system. A PAG template was created using the International Consortium Brain Mapping 152 gray matter model, and the individual PAG segment was developed by applying the deformation field from the structural image segment to the PAG template. A grey level co-occurrence matrix was used to calculate the texture parameters including the angular second moment (ASM), contrast, correlation, inverse difference moment (IDM) and entropy.

Results

There was a significant difference for ASM, IDM and entropy in the EM group (998.629 ± 0.162 × 10⁻³, 999.311 ± 0.073 × 10⁻³, 916.354 ± 0.947 × 10⁻⁵) compared to that found in the NC group (998.760 ± 0.110 × 10⁻³, 999.358 ± 0.037 × 10⁻³ and 841.198 ± 0.575 × 10⁻⁵) (p < 0.05). The entropy was significantly lower among the patients with CM (864.116 ± 0.571 × 10⁻⁵) than that found among patients with EM (p < 0.05). The area under the receiver operating characteristic curve was 0.776 and 0.750 for ASM and entropy in the distinction of the EM from NC groups, respectively. ASM was negatively related to disease duration (DD) and the Migraine Disability Assessment Scale (MIDAS) scores in the EM group, and entropy was positively related to DD and MIDAS in the EM group (p < 0.05).

Conclusion

The present study identified altered MR image texture characteristics of the PAG in EM. The identified texture characteristics could be considered as imaging biomarkers for EM.

Volume expansion of periaqueductal gray in episodic migraine: a pilot MRI structural imaging study

Background

The periaqueductal gray (PAG) dysfunction was recognized in migraine, and the nonspecific PAG lesions were also observed in episodic migraine (EM) recently. However, the PAG volume change was not totally detected in EM up to now. Herein, the aim of this study was to investigate altered PAG volume in EM patients based on high resolution brain structural image.

Methods

The brain structural images were obtained from 18 normal controls (NC), 18 EM patients and 16 chronic migraine (CM) on 3.0 T MR system. PAG template was created based on the ICBM152 gray matter template using MRIcron, and the individual PAG was created by applying the deformation field to the PAG template after structural image segment. One-way analysis of covariance, partial correlation analysis and Receiver operating characteristics (ROC) curve were applied.

Results

EM had a larger PAG volume (0.35 ± 0.02 ml) than that (0.32 ± 0.02 ml) of NC (P = 0.017). The PAG volume of CM (0.33 ± 0.02 ml) was negatively related to the VAS score (P = 0.03). ROC analysis demonstrated that PAG volume has higher diagnostic efficacy (AUC, 0.731; Sensitivity, 0.556; Specificity, 0.889) for NC vs. EM compared with that NC vs. CM (AUC, 0.634; Sensitivity, 0.438; Specificity, 0.833) and EM vs. CM (AUC, 0.618; Sensitivity, 0.813; Specificity, 0.556).

Conclusion

PAG volume expansion may be the direct impairment evidence on the brain in EM, and could be considered as a diagnostic and evaluated imaging biomarker in migraine.

Texture features of periaqueductal gray in the patients with medication-overuse headache

BACKGROUND

Periaqueductal gray (PAG) is the descending pain modulatory center, and PAG dysfunction had been recognized in migraine. Here we propose to investigate altered PAG texture features (quantitative approach for extracting texture descriptors for images) in the patients with medication-overuse headache (MOH) based on high resolution brain structural image to understand the MOH pathogenesis.

METHODS

The brain structural images were obtained from 32 normal controls (NC) and 44 MOH patients on 3.0 T MR system. PAG template was created based on the ICBM152 gray matter template, and the individual PAG segment was performed by applying the deformation field to the PAG template after structural image segment. Grey-level co-occurrence matrix (GLCM) was performed to measure the texture parameters including angular second moment (ASM), Contrast, Correlation, inverse difference moment (IDM) and Entropy.

RESULTS

Contrast was increased in MOH patients (9.28 ± 3.11) compared with that in NC (7.94 ± 0.65) (P < 0.05), and other texture features showed no significant difference between MOH and NC (P > 0.05). The area under the ROC curve was 0.697 for Contrast in the distinction of MOH from NC, and the cut-off value of Contrast was 8.11 with sensitivity 70.5% and specificity 62.5%. The contrast was negatively with the sleep scores (r = -0.434, P = 0.003).

CONCLUSION

Texture Contrast could be used to identify the altered MR imaging characteristics in MOH in understanding the MOH pathogenesis, and it could also be considered as imaging biomarker in for MOH diagnosis.

Volume gain of periaqueductal gray in medication-overuse headache

BACKGROUND

Periaqueductal gray (PAG) is a substantial descending pain modulatory center, and previous voxel-based morphometry study confirmed the clusters with increased volume in PAG region in medication-overuse headache (MOH). The aim of this study is to investigate altered PAG volume in MOH using an automated PAG segment method to measure the true PAG volume.

METHODS

High resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MR images were obtained from 22 patients with MOH and 22 normal controls (NC). PAG template was created based on ICBM 152 gray template, and the individual PAG was generated by applying the deformation field from structural image segment to the PAG template, and individual PAG volume was calculated.

RESULTS

There was a significant increased volume of PAG in MOH (0.366 ± 0.005 ml) than that in NC (0.341 ± 0.005 ml)(P < 0.05). There was no significant correlation between the PAG volume and the clinical variables in MOH patients (P > 0.05). The area of receiver operating characteristic (ROC) curve was 0.845, and the cut-off of PAG volume was 0.341 ml with sensitivity 95.5% and specificity 63.6%.

CONCLUSION

The present study demonstrated that the PAG volume gain was confirmed in MOH patients, and the automated individual PAG volume measure may be considered as a simple and effective imaging biomarker in MOH diagnosis.

Nonspecific periaqueductal gray lesions on T2WI in episodic migraine

Background

The specific periaqueductal gray (PAG) lesions with migraine-like headache were easily identified on conventional MR images in clinical practice, and the aim of this study is to investigate the nonspecific periaqueductal gray (PAG) lesions in episodic migraine (EM) patients based on T2 weighted imaging (T2WI).

Methods

T2WI images were obtained from 18 EM patients and 18 normal controls (NC) on 3.0 T MR system. The images were observed by two experienced radiologists, and the lesions were identified on T2WI by consensus by 2 experienced neuroradiologists blinded to the patient identity. Chi-Square test was performed for the significance test.

Results

Ring-like hyperintensity lesions (HILs) around the PAG region were observed in 14 EM patients and in 5 NCs on T2WI. Four EM patients and 13 NCs were normal in PAG region. The significance was revealed by Chi-Square test (P = 0.003).

Conclusion

HIL of PAG may be the direct evidence of the EM genesis, and the further structural and functional study should be performed to elucidate the neuromechanism of migraine pathogenesis.