Migraine Pathophysiology and its Clinical Implications

Migraine versus tension-type headache in automatic emotional processing: A visual mismatch negativity study

OBJECTIVE

It is important to discriminate different headaches in clinical practice, and neurocognitive biomarkers may serve as objective tools. Several reports have suggested potential cognitive impairment for primary headaches, whereas cognitions within specific domains remain elusive, e.g., emotional processing. In this study, we aimed to characterize processing of facial expressions in migraine and tension-type headache (TTH) by analyzing expression-related visual mismatch negativity (EMMN) and explored whether their processing patterns were distinct.

METHODS

Altogether, 73 headache patients (20 migraine with aura (MA), 28 migraine without aura (MwoA), 25 TTH) and 27 age-matched healthy controls were recruited. After a battery of mood/neuropsychological evaluations, an expression-related oddball paradigm containing multiple models of neutral, happy and sad faces was used to investigate automatic emotional processing.

RESULTS

We observed cognitive impairment in all headache patients, especially in attention/execution subdomains, but no discrepancy existed among different headaches. Although analyses of P1/N170 did not reach significant levels, amplitude of early and late EMMN was markedly diminished in MA and MwoA compared with controls and TTH, regardless of happy or sad expression. Moreover, sad EMMN was larger (more negative) than happy EMMN only in controls, while not in all headache groups.

CONCLUSIONS

Our findings implied that migraine, rather than TTH, might lead to more severe impairment of automatic emotional processing, which was manifested as no observable EMMN elicitation and disappearance of negative bias effect. The EMMN component could assist in discrimination of migraine from TTH and diagnosis of undefined headaches, and its availability needed further validations.

Oxygen Straight to the Brain: An Overview of Hyperbaric Oxygen Therapy for a Variety of Brain Morbidities

ABSTRACT

Hyperbaric oxygen therapy as a treatment for conditions like traumatic brain injury, posttraumatic stress disorder, and migraines would seem intuitive, given its effect on condition-related ischemia and inflammation. However, hyperbaric therapeutic impacts for these in acute and chronic, or prolonged symptoms are elusive. This narrative review of hyperbaric's utility provided in sections per disease renders first a review of conventional pathological mechanisms and then articulates hyperbaric treatment targets versus their respective impacts. Multiple challenges exist using hyperbaric oxygen therapy for each morbidity, even in tertiary and adjunctive treatments. An almost universal shortfall across studies includes a lack of consistent, appropriate patient selection criteria intersected with delivery timing of therapy to symptomatic target, necessary to provide a higher fidelity in treatment metrics. Further research into these respective conditions is needed along with a revisitation of hyperbaric oxygen therapy's application to their conventional pathological mechanisms, lending new perspective to their employment and efficacy.

Drug-related side effects and adverse reactions in the treatment of migraine: a bibliometric and visual analysis

Background

Migraine imposes a substantial global burden, impacting patients and society. Pharmacotherapy, as a primary treatment, entails specific adverse reactions. Emphasizing these reactions is pivotal for improving treatment strategies and enhancing patients' well-being. Thus, we conducted a comprehensive bibliometric and visual analysis of relevant literature.

Methodology

We conducted a comprehensive search on the Science Citation Index Expanded within the Web of Science, restricting the literature for analysis based on criteria such as document type, publication date, and language. Subsequently, we utilized various analytical tools, including VOSviewer, Scimago Graphica, the R package 'bibliometrix', CiteSpace, and Excel programs, for a meticulous examination and systematic organization of data concerning journals, authors, countries/regions, institutions, keywords, and references.

Results

By August 31, 2023, the literature was distributed across 379 journals worldwide, authored by 4,235 individuals from 1726 institutions. It featured 2,363 keywords and 38,412 references. 'HEADACHE' led in publication count, with 'SILBERSTEIN S' as the most prolific author. The United States ranked highest in publication volume, with 'UNIV COPENHAGEN' leading among institutions.

Conclusion

Our research findings indicate that researchers in the field continue to maintain a focus on the calcitonin gene-related peptide (CGRP) system and explore diverse mechanisms for drug development through the application of novel biotechnological approaches. Furthermore, it is imperative to enhance the assessment of clinical trial outcomes, consistently monitor the efficacy and safety of prominent drugs such as Erenumab and Fremanezumab. There is a need for further evaluation of acute and preventive treatments tailored to different populations and varying types of migraine.

Drug-related side effects and adverse reactions in the treatment of migraine: a bibliometric and visual analysis

BACKGROUND

Migraine imposes a substantial global burden, impacting patients and society. Pharmacotherapy, as a primary treatment, entails specific adverse reactions. Emphasizing these reactions is pivotal for improving treatment strategies and enhancing patients' well-being. Thus, we conducted a comprehensive bibliometric and visual analysis of relevant literature.

METHODOLOGY

We conducted a comprehensive search on the Science Citation Index Expanded within the Web of Science, restricting the literature for analysis based on criteria such as document type, publication date, and language. Subsequently, we utilized various analytical tools, including VOSviewer, Scimago Graphica, the R package 'bibliometrix', CiteSpace, and Excel programs, for a meticulous examination and systematic organization of data concerning journals, authors, countries/regions, institutions, keywords, and references.

RESULTS

By August 31, 2023, the literature was distributed across 379 journals worldwide, authored by 4,235 individuals from 1726 institutions. It featured 2,363 keywords and 38,412 references. 'HEADACHE' led in publication count, with 'SILBERSTEIN S' as the most prolific author. The United States ranked highest in publication volume, with 'UNIV COPENHAGEN' leading among institutions.

CONCLUSION

Our research findings indicate that researchers in the field continue to maintain a focus on the calcitonin gene-related peptide (CGRP) system and explore diverse mechanisms for drug development through the application of novel biotechnological approaches. Furthermore, it is imperative to enhance the assessment of clinical trial outcomes, consistently monitor the efficacy and safety of prominent drugs such as Erenumab and Fremanezumab. There is a need for further evaluation of acute and preventive treatments tailored to different populations and varying types of migraine.

Multimodal Migraine Management and the Pursuit of Migraine Freedom: A Narrative Review

Migraine is a neurologic disease with a complex pathophysiology that can be controlled with current treatment options but not cured. Therefore, treatment expectations are highly variable. The concept of migraine freedom was recently introduced and can mean different things, with some, for example, expecting complete freedom from headache and associated symptoms and others accepting the occasional migraine attack if it does not impact functioning. Therefore, migraine management should be optimized so that patients can have the best opportunity to achieve their optimal treatment goals. With migraine freedom as a goal and, given the complex pathophysiology of migraine and the high incidence of comorbidities among individuals with migraine, treatment with a single modality may be insufficient, as it may not achieve migraine freedom in those with more frequent or disabling attacks. In this clinical perspective article, we have identified four key, partially overlapping principles of multimodal migraine treatment: (1) manage common comorbidities; (2) control modifiable risk factors for progression by addressing medication and caffeine overuse; (3) diagnose and treat secondary causes of headache, if present; and (4) individualize acute and preventive treatments to minimize pain, functional disability, and allodynia. There are many barriers to pursuing migraine freedom, and strategies to overcome them should be optimized. Migraine freedom should be an aspirational goal both at the individual attack level and for the disease overall. We believe that a comprehensive and multimodal approach that addresses all barriers people with migraine face could move patients closer to migraine freedom.

A Bibliometric and Scientific Knowledge Map Study of Migraine Treatment from 2013 to 2022

Background

Migraine treatment research has made much great progress over the past decade. However, there have been few bibliometric studies conducted so far. In this study, bibliometric analysis was used to explore the current status and future trends of migraine treatment research.

Methods

Migraine treatment-related articles were retrieved from the Web of Science Core Collection on December 7, 2022. Quantitative variables were analyzed by the R-tool bibliometrix and Excel 2020. VOS viewer and CiteSpace software were used to visualize citation, co-authorship, co-occurrence, and co-citation analysis of countries/regions, organizations, authors, references, and keywords.

Results

A total of 3294 articles were included with the global publication output showing a slow upward trend. The United States was the most productive country with 1116 papers and gained the most citations. Albert Einstein College of Medicine was the most active institution with 176 papers. Headache published the most articles in this domain, while Cephalalgia was the most commonly co-cited journal. Lipton, RB published the most articles and had the most citations. Tepper S, 2017, Lancet neurology and Silberstein S, 2004, Cephalalgia were defined as classic articles. The current research mainly focuses on CGRP-related therapeutics, such as fremanezumab, erenumab and ubrogepant.

Conclusion

Based on the analysis of bibliometric data on migraine treatment over the past decade, the trends and the knowledge graph of the country, organization, author, reference, and the keyword were identified, providing accurate and quick positioning of the critical information in the domain.

Arterial spin labeling MRI applied to migraine: current insights and future perspectives

INTRODUCTION

Advanced neuroimaging techniques have extensively contributed to elucidate the complex mechanisms underpinning the pathophysiology of migraine, a neurovascular disorder characterized by episodes of headache associated with a constellation of non-pain symptoms. The present manuscript, summarizing the most recent progresses of the arterial spin labelling (ASL) MRI techniques and the most significant findings from ASL studies conducted in migraine, is aimed to clarify how ASL investigations are contributing to the evolving insight on migraine pathophysiology and their putative role in migraine clinical setting. ASL techniques, allowing to quantitatively demonstrate changes in cerebral blood flow (CBF) both during the attacks and in the course of interictal period, could represent the melting point between advanced neuroimaging investigations, conducted with pure scientific purposes, and conventional neuroimaging approaches, employed in the diagnostic decision-making processes.

MAIN BODY

Converging ASL evidences have demonstrated that abnormal CBF, exceeding the boundaries of a single vascular territory, with biphasic trend dominated by an initial hypoperfusion (during the aura phenomenon but also in the first part of the headache phase) followed by hyperperfusion, characterizes migraine with aura attack and can represent a valuable clinical tool in the differential diagnosis from acute ischemic strokes and epileptic seizures. Studies conducted during migraine without aura attacks are converging to highlight the involvement of dorsolateral pons and hypothalamus in migraine pathophysiology, albeit not able to disentangle their role as "migraine generators" from mere attack epiphenomenon. Furthermore, ASL findings tend to support the presence of perfusion abnormalities in brain regions known to be involved in aura ignition and propagation as well as in areas involved in multisensory processing, in both patients with migraine with aura and migraine without aura.

CONCLUSION

Although ASL studies have dramatically clarified quality and timing of perfusion abnormalities during migraine with aura attacks, the same cannot be said for perfusion changes during migraine attacks without aura and interictal periods. Future studies with more rigorous methodological approaches in terms of study protocol, ASL technique and sample selection and size are mandatory to exploit the possibility of better understanding migraine pathophysiology and identifying neuroimaging biomarkers of each migraine phase in different migraine phenotypes.

Immune Fitness, Migraine, and Headache Complaints in Individuals with Self-Reported Impaired Wound Healing

Background

Having chronic wounds and impaired wound healing are associated with psychological distress. The current study aims to evaluate migraine and headache complaints in young adults with self-reported impaired wound healing.

Methods

A survey was conducted among N=1935 young adults (83.6% women), 18-30 years old, living in the Netherlands. Wound healing status was verified, immune fitness was assessed using a single-item rating scale, and ID Migraine was completed. In addition, several questions were answered on past year's headache experiences (including frequency, quantity, type, location, and severity).

Results

In both the control group (p < 0.001) and the IWH group (p = 0.002) immune fitness was significantly lower among those that reported headaches compared to those that reported no headaches. Individuals with self-reported impaired wound healing (IWH) scored significantly higher on the ID Migraine scale, and individuals of the IWH group scored significantly more often positive for migraine (ie, an ID Migraine score ≥2). They reported a younger age of onset of experiencing headaches, and significantly more often reported having a beating or pounding headache than the control group. Compared to the control group, the IWH group reported being significantly more limited in their daily activities compared to the control group.

Conclusion

Headaches and migraines are more frequently reported by individuals with self-reported impaired wound healing, and their reported immune fitness is significantly poorer compared to healthy controls. These headache and migraine complaints significantly limit them in their daily activities.

Prevalence of Ponticulus Posticus and Migraine in 220 Orthodontic Patients: A Cross-Sectional Study

BACKGROUND

Ponticulus posticus (PP) is a medical term that describes an anomaly of the atlas (C1), which has a complete or partial bone bridge over the vertebral artery (VA) groove. The purpose of the study is to estimate the prevalence of PP in patients with a diagnosis of migraine.

METHODS

Cone beam CT (CBCT) scans (n = 220) were reviewed for the detection of PP in the University "G. D'Annunzio" of Chieti in the Department of Medical, Oral and Biotechnological Sciences. The sample included 220 Italian patients between 18 and 87 years. Pearson chi-square analysis (p < 0.05 and 95% CI) was used to establish an association between migraine and PP.

RESULTS

The present study found a prevalence of PP of 20.9% and a prevalence of migraine of 12.272%. The association between migraine and PP was confirmed by the chi-square statistic, since the p-value was 0.008065 (significant at p < 0.05). PP was more frequent in the migraine without aura group, without a statistical difference relative to the migraine with aura group.

CONCLUSIONS

The study concluded that PP is positively associated with migraine.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Evaluation of a Polyherbal Formulation on the Management of Migraine Headaches due to Functional Dyspepsia: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial

A holistic concept based on traditional Persian medicine (TPM) describes a headache with a gastrointestinal (GI) origin (gastric-headache). Although the neurological manifestations of this headache are similar to those of other headaches, its etiology is different. Considering its simultaneous effects on the brain and GI system, a formulation was designed based on this concept. This study aimed to determine the safety and efficacy of the designed formulation on migraine headache (MH) associated with functional dyspepsia (FD). A total of 75 diagnosed cases of MH patients with concurrent FD were randomly divided equally into 3 groups: (i) the polyherbal formulation, sodium valproate (VPA), and amitriptyline group, (ii) VPA, amitriptyline, and polyherbal formulation placebo group, and (iii) the polyherbal formulation and VPA placebo group. The primary outcomes, including frequency, duration, and severity of MH attacks, were measured at baseline and weeks 4, 8, and 12. However, secondary outcomes, including the Headache Impact Test 6 (HIT-6) Questionnaire and Parkman's score, were evaluated at baseline and end of treatment. The frequency, duration, and severity of migraine (P < 0.001 for all cases), HIT-6 (P < 0.001 for all cases), and FD (P < 0.001 for all cases) scores at the end of treatment showed a significant decrease in the 3 groups compared to the baseline. However, the differences in those variables between the 3 groups were not significant at the end of the study. The polyherbal formulation alone may improve the symptoms of migraine patients and other groups. This effect could be due to improving digestion and FD in migraine patients.

A bibliometric analysis and visualization of tension-type headache

Background

Tension-type headache (TTH) is the most prevalent headache in the clinical practice, leading to impaired social activities, work-related disability, and heavy financial burdens. Previous studies have described possible inducement, potential pathophysiology, and clinical management of TTH; however, due to the lack of attention, literature involving bibliometric analysis is sporadic. Therefore, this study aimed to explore the current hotspots and future directions of the TTH field by bibliometric analysis.

Methods

By using CiteSpace and VOSviewer, literature regarding TTH between 2002 and 2021 from the Web of Science database was summarized and extracted. Annual publication trend, the most productive countries/regions and institutions, distribution of categories, co-citation of journals and references, and co-occurrence of keywords were analyzed.

Results

A total of 3,379 publications were included in the final visualization, indicating a stable trend in current research and a lack of breakthroughs over the past decades. These studies were mainly conducted in 120 countries/regions led by the United States and more than 600 institutions. Four eternal core themes were identified in TTH, including neurosciences, nursing, developmental psychology, and general/internal medicine. Cephalalgia ranked first, with the highest number of literature, and is the most influential journal in this area. Keyword analysis demonstrated that the similarities and differences between migraine and TTH, epidemiological studies, clinical double-blind trials, and potential populations have become key issues in the TTH field.

Conclusion

TTH has received less attention and breakthroughs in the past 20 years. To promote coordinated development between regions to fight headaches, cooperation and exchanges between countries and institutions are essential in the future. Relevant studies about headaches in children and adolescents, inducing factors such as emotional triggers and sleep disorders, concomitant diseases, possible pathogenesis, and headache treatments, are in the spotlight in recent years. This study offers a powerful roadmap for further research in this field.

Contribution of tetrodotoxin-resistant persistent Na+ currents to the excitability of C-type dural afferent neurons in rats

BACKGROUND

Growing evidence supports the important role of persistent sodium currents (I_NaP) in the neuronal excitability of various central neurons. However, the role of tetrodotoxin-resistant (TTX-R) Na⁺ channel-mediated I_NaP in the neuronal excitability of nociceptive neurons remains poorly understood.

METHODS

We investigated the functional role of TTX-R I_NaP in the excitability of C-type nociceptive dural afferent neurons, which was identified using a fluorescent dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchloride (DiI), and a whole-cell patch-clamp technique.

RESULTS

TTX-R I_NaP were found in most DiI-positive neurons, but their density was proportional to neuronal size. Although the voltage dependence of TTX-R Na⁺ channels did not differ among DiI-positive neurons, the extent of the onset of slow inactivation, recovery from inactivation, and use-dependent inhibition of these channels was highly correlated with neuronal size and, to a great extent, the density of TTX-R I_NaP. In the presence of TTX, treatment with a specific I_NaP inhibitor, riluzole, substantially decreased the number of action potentials generated by depolarizing current injection, suggesting that TTX-R I_NaP are related to the excitability of dural afferent neurons. In animals treated chronically with inflammatory mediators, the density of TTX-R I_NaP was significantly increased, and it was difficult to inactivate TTX-R Na⁺ channels.

CONCLUSIONS

TTX-R I_NaP apparently contributes to the differential properties of TTX-R Na⁺ channels and neuronal excitability. Consequently, the selective modulation of TTX-R I_NaP could be, at least in part, a new approach for the treatment of migraine headaches.

Effectiveness and acceptability of noninvasive brain and nerve stimulation techniques for migraine prophylaxis: a network meta-analysis of randomized controlled trials

BACKGROUND

Current pharmacologic prophylactic strategies for migraine have exhibited limited efficacy, with response rates as low as 40%-50%. In addition to the limited efficacy, the acceptability of those pharmacologic prophylactic strategies were unacceptable. Although noninvasive brain/nerve stimulation strategies may be effective, the evidence has been inconsistent. The aim of this network meta-analysis (NMA) was to compare strategies of noninvasive brain/nerve stimulation for migraine prophylaxis with respect to their effectiveness and acceptability.

METHODS

The PubMed, Embase, ScienceDirect, ProQuest, ClinicalTrials.gov , ClinicalKey, Cochrane CENTRAL, Web of Science, and ClinicalTrials.gov databases were systematically searched to date of June 4th, 2021 for randomized controlled trials (RCTs). Patients with diagnosis of migraine, either episodic migraine or chronic migraine, were included. All NMA procedures were conducted under the frequentist model.

RESULTS

Nineteen RCTs were included (N = 1493; mean age = 38.2 years; 82.0% women). We determined that the high frequency repetitive transcranial magnetic stimulation (rTMS) over C3 yielded the most decreased monthly migraine days among all the interventions [mean difference = - 8.70 days, 95% confidence intervals (95%CIs): - 14.45 to - 2.95 compared to sham/control groups]. Only alternating frequency (2/100 Hz) transcutaneous occipital nerve stimulation (tONS) over the Oz (RR = 0.36, 95%CIs: 0.16 to 0.82) yielded a significantly lower drop-out rate than the sham/control groups did.

CONCLUSIONS

The current study provided a new direction for the design of more methodologically robust and larger RCTs based on the findings of the potentially beneficial effect on migraine prophylaxis in participants with migraine by different noninvasive brain/nerve stimulation, especially the application of rTMS and tONS.

TRIAL REGISTRATION

CRD42021252638. The current study had been approval by the Institutional Review Board of the Tri-Service General Hospital, National Defense Medical Center (TSGHIRB No. B-109-29).

Scientific Knowledge Graph of Acupuncture for Migraine: A Bibliometric Analysis from 2000 to 2019

OBJECTIVE

This study aims to explore the trend and knowledge mapping of acupuncture for migraine through bibliometrics.

METHODS

It retrieved the literature on acupuncture for migraine in the Web of Science database from 2000 to 2019, and then resorted to CiteSpace to conduct bibliometric analysis to attain the knowledge mapping.

RESULTS

The total number of publications each year has increased year by year, and the average annual growth rate from 2000 to 2009 was 15.57%, while from 2010 to 2019 was 6.35%, with a faster growth rate from 2000 to 2009. According to the cluster analysis of institutions, authors, cited references, and keywords, 10, 7, 12, and 10 categories were gained from 2000 to 2019. The most productive countries, institutions, and authors are the USA and China, Technical University of Munich and Beijing University of Chinese Medicine, Linde K and Liang FR from 2000 to 2019, whose frequency is 119/103, 28/24, and 28/24, respectively. However, the most important of them are Canada, Sichuan University, and Witt CM. Owing to their highest centrality, they are 0.86, 0.54, and 0.27 separately. Moreover, cited references that contributed to the most co-citations are Linde K (2005), yet, the most vital cited reference is Karst M (2001). Keywords such as migraine, acupuncture, headache, pain, and randomized controlled trial are the most frequently used. However, needle acupuncture is the crucial keyword. In the cluster analysis of institutions, authors, cited references, and keywords from 2000 to 2019, the largest cluster categories are #0 migraine prophylaxis, #1 randomized controlled trial, #0 episodic migraine, and #0 topiramate treatment. Then, randomized controlled trials of acupuncture prevention and treatment of migraine are the most important research content in this field.

CONCLUSION

Through the bibliometric analysis of the research on acupuncture for migraine in the Web of Science database in the past 20 years, the trends and the Knowledge Graph of the country, institution, author, cited reference, and the keyword are acquired, which have an important guiding significance for quickly and accurately positioning the key information in the field.

Retinal nerve fiber layer and ganglion cell layer changes using optical coherence tomography in patients with chronic migraine: a case-control study

Background

Migraine is a prevalent, chronic, and multifactorial neurovascular disease.

Objectives

Our work aimed to investigate if the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness are affected in patients with chronic migraine to improve the understanding of the etiology and pathophysiology of migraine.

Subjects and methods

A case-control study conducted on 30 patients with chronic migraine and 30 aged and sex-matched healthy controls. Subjects underwent full neurological and ophthalmological history, ophthalmological examination, and measuring RNFL and GCL thickness using the spectral domain-optical coherence tomography (SD-OCT).

Results

RNFL thinning (average, superior, inferior, nasal, and temporal) was significantly more in patients with chronic migraine than healthy control (P = 0.001, 0.022, 0.045, 0.034, and 0.001, respectively). No statistically significant difference was found between chronic migraine patients and healthy controls regarding GCL thickness (average, superior, and inferior) (P value ˃ 0.05).

The average RNFL thickness was significantly thinner in migraine with aura (MwA) than migraine without aura (MwoA) (P = 0.006). The average GCL thickness was thinner in MwA than MwoA (P = 0.039). No statistically significant difference was found between the eyes on the side of the headache and the eyes of the contralateral side regarding RNFL and GCL thickness (P value ˃ 0.05). Age at onset, disease duration, headache frequency, and headache intensity showed an insignificant correlation with OCT parameters.

Conclusion

Retinal changes could be an association with chronic migraine that may be used as a biomarker.

Effect of Acupuncture on the p38 Signaling Pathway in Several Nervous System Diseases: A Systematic Review

Acupuncture is clinically used to treat various diseases and exerts positive local and systemic effects in several nervous system diseases. Advanced molecular and clinical studies have continually attempted to decipher the mechanisms underlying these effects of acupuncture. While a growing understanding of the pathophysiology underlying several nervous system diseases shows it to be related to inflammation and impair cell regeneration after ischemic events, the relationship between the therapeutic mechanism of acupuncture and the p38 MAPK signal pathway has yet to be elucidated. This review discusses the latest advancements in the identification of the effect of acupuncture on the p38 signaling pathway in several nervous system diseases. We electronically searched databases including PubMed, Embase, and the Cochrane Library from their inception to April 2020, using the following keywords alone or in various combinations: "acupuncture", "p38 MAPK pathway", "signaling", "stress response", "inflammation", "immune", "pain", "analgesic", "cerebral ischemic injury", "epilepsy", "Alzheimer's disease", "Parkinson's disease", "dementia", "degenerative", and "homeostasis". Manual acupuncture and electroacupuncture confer positive therapeutic effects by regulating proinflammatory cytokines, ion channels, scaffold proteins, and transcription factors including TRPV1/4, Nav, BDNF, and NADMR1; consequently, p38 regulates various phenomena including cell communication, remodeling, regeneration, and gene expression. In this review article, we found the most common acupoints for the relief of nervous system disorders including GV20, GV14, ST36, ST37, and LI4. Acupuncture exhibits dual regulatory functions of activating or inhibiting different p38 MAPK pathways, contributing to an overall improvement of clinical symptoms and function in several nervous system diseases.

Topographic changes measured by the swept source optical coherence tomography in retinal nerve fiber layer, optic nerve head and macula in children with migraine

As a vascular-inflammatory disease, migraine affects the brain and some other organs, such as the eye. The aim of this study was to measure and compare the peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell layer thickness and optic nerve head parameters to detect structural damage in children with migraine using swept-source optical coherence tomography. Twenty-four children with migraine in the painless period and 26 controls were included in the study. The vast majority of the groups consisted of females (75% for patients and 77% for controls). Certain RNFL quadrants and optic disc parameters revealed significant differences between the patients and controls. In the right and left eyes of children with migraine, nasal quadrant RNFL was significantly thicker than that in healthy subjects (88.82 ± 11.03 vs 77.80 ± 13.77, P = 0.004 for right eyes and 87.71 ± 11.79 vs 77.80 ± 13.77, P = 0.01 for left eyes). Temporal quadrant RNFL in the left eyes was thinner (78.67 ± 9.57 vs 84.44 ± 9.68, P = 0.04). Disc area in the left eyes of the patients was greater (2.29 ± 0.46 vs 1.94 ± 0.28, P = 0.003). There were significant expansions in cup volumes in favor of the patients for right and left eyes (0.15 ± .0.19 vs 0.05 ± 0.05, P = 0.03 and 0.17 ± 0.14 vs 0.05 ± 0.05, P = 0.001, respectively). The only significant difference between the left and right eyes of the migraineurs was the RNFL thickness in the superior quadrant. Ganglion cell layer thickness did not differ between the right eyes, left eyes and controls. In conclusion, children with migraine showed significant variations in specific RNFL and optic disc parameters compared to control subjects.

Migraine Headache and Risk of Dementia in the Atherosclerosis Risk in Communities Neurocognitive Study

OBJECTIVE

We aimed to assess the association between migraine headache and incident dementia.

BACKGROUND

Migraine is a risk factor for white matter hyperintensities and ischemic stroke, which are both associated with increased risk of dementia. However, it is unknown whether migraine is independently associated with dementia.

METHODS

History of migraine was ascertained via questionnaire. Adjudicated cases of dementia were identified using cognitive tests, neuropsychological exams, and clinician review of suspected cases. Incident dementia was identified using adjudicated cases, follow-up calls, and surveillance of hospital and death codes. We assessed hazards of incident dementia by migraine status. Sex differences were also examined and stratified results were presented.

RESULTS

Analysis included 12,495 White and African American participants ages 51-70 with a median follow-up time of 21 years. Prevalence of dementia was 18.5% (1821/9955) among those with no migraine history, 15.8% (196/1243) among those with severe non-migraine heading, and 16.7% (233/1397) among migraineurs. There was no association between migraine and incident dementia [hazard ratio: 1.04 (0.91, 1.20)]. There was also no statistically significant interaction between sex and migraine status on risk of dementia.

CONCLUSION

Despite evidence of brain abnormalities in migraineurs, there was no association between migraine and incident dementia in this prospective cohort.

Fluctuations in local and widespread mechanical sensitivity throughout the migraine cycle: a prospective longitudinal study

BACKGROUND

People with migraine have localised (i.e., cephalic) mechanical sensitivity. There is uncertainty regarding widespread (i.e., extra-cephalic) mechanical sensitivity and variations in mechanical sensitivity throughout the migraine cycle. Therefore, this study aimed (1) to comprehensively assess mechanical sensitivity in both cephalic and extra-cephalic regions during the preictal, ictal, postictal and interictal phases; and (2) to compare these findings with mechanical sensitivity at corresponding time-points and locations in healthy participants.

METHODS

According to sample size calculations, 19 people with migraine and 19 matched healthy volunteers participated in a prospective longitudinal study. Pressure pain thresholds were evaluated in three cephalic regions (temporalis, upper trapezius and C1 paraspinal muscles) and two extra-cephalic regions (extensor carpi radialis and tibialis anterior muscle) with a digital algometer during the four phases of the migraine cycle in people with migraine and at corresponding intervals and locations in healthy participants. Linear mixed model analyses with a random intercept were used.

RESULTS

People with migraine had increased mechanical sensitivity in cephalic and extra-cephalic regions in all phases of the migraine cycle compared to healthy participants. Furthermore, this mechanical sensitivity was more severe in the preictal, ictal and postictal phase compared to the interictal phase in cephalic and extra-cephalic regions.

CONCLUSION

People with migraine have localised as well as widespread mechanical sensitivity compared to healthy participants. This sensitivity is even more pronounced immediately before, during and after a migraine attack.

Quantitative analysis of the retinal nerve fiber layer, ganglion cell layer and optic disc parameters by the swept source optical coherence tomography in patients with migraine and patients with tension-type headache

The aim of the study was to measure the thicknesses of the inner retinal segments and optic nerve head (ONH) parameters in migraineurs and patients with tension-type headache (TTH) in headache-free period using swept source optical coherence tomography (SS-OCT) and to compare the outcomes with each other and those of healthy subjects. The study population consisted of 23 migraineurs, 22 TTH patients, and 25 controls with a best-corrected visual acuity of 20/20 and without a history of systemic or ocular disease. Macular ganglion cell inner plexiform layer (mGCIPL), macular ganglion cell complex (mGCC), circumpapillary retinal nerve fiber layer (cpRNFL), and ONH parameters were evaluated using SS-OCT, and the areas under the receiver-operating characteristic (ROC) curves were calculated to determine the ability of these parameters to distinguish between the patient and normal eyes. There were not statistically significant differences between the measurements acquired from migraineurs, TTH patients, and the controls. The outcomes of the patients with TTH were very similar to those of the normal participants. The areas under the ROC curves (AUC) correlated highly with the measurements obtained from the same subfields for the mGCC, MGCIPL, cpRNFL, and ONH parameters. In conclusion, SS-OCT presented reproducible and reliable measurements of posterior segment layers of the eyes, especially in sectoral configuration, and the parameters did not show significant difference between the groups.

Associated Factors and Clinical Implication of Cutaneous Allodynia in Patients with Cluster Headache: A Prospective Multicentre Study

Cutaneous allodynia (CA) is an abnormal pain in response to non-painful stimuli. In the present study, we sought to investigate the presence of CA, its associated factors, and its clinical implications in patients with cluster headache (CH). In this cross-sectional study, we analysed data from a prospective multicentre registry enrolling consecutive patients with CH. We identified CA during and between headache attacks using the 12-item Allodynia Symptom Checklist (ASC) administered during the CH bout period. Comorbid depression and anxiety were ascertained using the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder (GAD-7) scales. Headache impact was evaluated using the Headache Impact Test-6 (HIT-6). Of 119 eligible patients, 48 and two (40.3% and 1.7%) had CA during and between headache attacks, respectively. In univariable analyses, total CH duration, major depressive disorder (MDD), and generalized anxiety disorder (GAD) were associated with CA during headache attack. They remained significantly associated with CA during headache attack in multivariable analyses. Patients with CA during headache attack had higher headache impact (P = 0.002). A “50% responder” analysis showed no difference in outcome of acute and preventive treatment between patients with and without CA during headache attack. Patients with CH commonly experienced CA during headache attack, but not between headache attacks. CA during headache attack was associated with disease duration, depression, and anxiety.

Tonic regulation of middle meningeal artery diameter by ATP-sensitive potassium channels

Activation of ATP-sensitive potassium (KATP) channels in arterial smooth muscle (ASM) contributes to vasodilation evoked by a variety of endogenous and exogenous compounds. Although controversial, activation of KATP channels by neuropeptides such as calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase activating peptide (PACAP) in the trigeminovascular system, including the middle meningeal artery (MMA), has been linked to migraine headache. The objective of the current study was to determine if ongoing KATP channel activity also influences MMA diameter. In the absence of other exogenous compounds, the KATP channel inhibitors glibenclamide and PNU37883A induced constriction of isolated and pressurized MMAs. In contrast, KATP channel inhibition did not alter cerebral artery diameter. Consistent with tonic KATP activity in MMA, glibenclamide also induced ASM membrane potential depolarization and increased cytosolic Ca2+. Inhibitors of cAMP-dependent protein kinase (PKA) abolished basal KATP activation in MMA and caused a marked decrease in sensitivity to the synthetic KATP channel opener, cromakalim. In vivo MMA constriction in response to gibenclamide was observed using two-photon imaging of arterial diameter. Together these results indicate that PKA-mediated tonic KATP channel activity contributes to the regulation of MMA diameter.

Making a new-patient headache education session more patient-centered: what participants want to know

Purpose: To describe the new-patient Education Session provided by the Calgary Headache Assessment and Management Program, analyze patient evaluations, and generate potential patient-centered improvements based on themes in patient feedback.Materials and Methods: Between 2008 and 2012, 1873 new patients attended the Education Session, and 913 evaluations were completed. Session objectives ratings were analyzed. Open-ended questions regarding most- and least-helpful components and suggestions for improvement were examined using thematic analysis.Results: Eighty-seven percent of respondents indicated they would recommend the session to others with headache. Median objectives ratings ranged from 9.0-10.0 out of 10 and were stable over time. Most-helpful themes included medication, types of headache, our program's multi-faceted management approach, medication overuse, triggers, and not feeling alone. Most respondents left the least-useful and suggestions sections blank or commented "nothing" or "not applicable". Least-useful themes included migraine overemphasis, insufficient or excessive medication content, participant over-disclosure, and lack of practical trigger management strategies.Conclusion: Most attendees found the Education Session useful. Those who did not provided valuable input that will allow us to modify the content. Our findings may benefit other headache programs seeking to implement or improve patient education programing. Implications for RehabilitationHeadache is a common and debilitating condition.Education is an important part of headache treatment, and has been associated with decreases in headache frequency, intensity, and disability, as well as increases in self-efficacy.A new-patient Education Session is a practical and inexpensive way to provide evidence-based medical and behavioral headache information.Quantitative and qualitative analysis of patient evaluations can help gauge relevance and direct content changes.

Migraine, Cyclic Vomiting Syndrome, and Other Gastrointestinal Disorders

PURPOSE OF REVIEW

Cyclic vomiting syndrome (CVS) is a chronic functional gastrointestinal disorder characterized by episodic nausea and vomiting and is diagnosed using Rome IV criteria. CVS is being recognized more frequently in adults with a prevalence of 2%. It is associated with several functional disorders like autonomic dysfunction, anxiety, and depression, but the strongest association is with migraine. We will elucidate the close relationship between migraine and CVS and briefly discuss its association with other gastrointestinal disorders.

RECENT FINDINGS

We highlight similarities in pathophysiology, clinical presentation, and response to medications between CVS and migraine (tricyclic antidepressants, triptans, antiepileptics). We also discuss novel therapies like CGRP inhibitors which are effective in migraine and have potential for adaptation in patients with CVS. Using migraine as a template should enable investigators to elucidate the mechanisms underlying this disorder, develop novel therapies, and direct future research in CVS.

Effect of carbamazepine on tetrodotoxin-resistant Na+ channels in trigeminal ganglion neurons innervating to the dura

Migraine is a neurological disorder characterized by recurrent and disabling severe headaches. Although several anticonvulsant drugs that block voltage-dependent Na⁺ channels are widely used for migraine, far less is known about the therapeutic actions of carbamazepine on migraine. In the present study, therefore, we characterized the effects of carbamazepine on tetrodotoxin-resistant (TTX-R) Na⁺ channels in acutely isolated rat dural afferent neurons, which were identified by the fluorescent dye DiI. The TTX-R Na⁺ currents were measured in medium-sized DiIpositive neurons using the whole-cell patch clamp technique in the voltage-clamp mode. While carbamazepine had little effect on the peak amplitude of transient Na⁺ currents, it strongly inhibited steady-state currents of transient as well as persistent Na⁺ currents in a concentration-dependent manner. Carbamazepine had only minor effects on the voltage-activation relationship, the voltage-inactivation relationship, and the use-dependent inhibition of TTX-R Na⁺ channels. However, carbamazepine changed the inactivation kinetics of TTX-R Na⁺ channels, significantly accelerating the development of inactivation and delaying the recovery from inactivation. In the current-clamp mode, carbamazepine decreased the number of action potentials without changing the action potential threshold. Given that the sensitization of dural afferent neurons by inflammatory mediators triggers acute migraine headaches and that inflammatory mediators potentiate TTX-R Na⁺ currents, the present results suggest that carbamazepine may be useful for the treatment of migraine headaches.

Involvement of the Tetraspanin 2 (TSPAN2) Gene in Migraine: A Case-Control Study in Han Chinese

Tetraspanin 2 (TSPAN2) belongs to the tetraspanin superfamily. Previous studies have identified significant associations of the TSPAN2 single nucleotide polymorphisms (SNPs) rs12134493 and rs2078371 with migraine in Western populations; however, these associations need to be confirmed in the Chinese Han population. In addition, we carried out further studies to see whether TSPAN2 is associated with susceptibility to migraine to provide new clinical evidence. A case-control study (425 patients with migraine and 425 healthy controls) in a Chinese Han population was performed to evaluate the associations between migraine and TSPAN2 via a genotype-phenotype analysis between TSPAN2 and clinical symptoms. The SNP rs2078371 was found to be significantly associated with migraines especially in migraines without aura (MO) and in female patients. Meta-analysis revealed that the A allele of rs12134493 was significantly associated with migraines (OR = 1.14, P = 0.0001). Our findings suggested that TSPAN2 is a potential susceptibility factor for migraines. To confirm our results, a large-scale Chinese Han population study should be conducted. Considering that these two SNPs have not been definitively shown to affect TSPAN2 or to regulate nearby genes in this genomic region, the biological function and molecular mechanism of TSPAN2 in migraine should be further explored.

The association between migraine and physical exercise

BACKGROUND

There is an unmet need of pharmacological and non-pharmacological treatment options for migraine patients. Exercise can be used in the treatment of several pain conditions, including. However, what exact role exercise plays in migraine prevention is unclear. Here, we review the associations between physical exercise and migraine from an epidemiological, therapeutical and pathophysiological perspective.

METHODS

The review was based on a primary literature search on the PubMed using the search terms "migraine and exercise".

RESULTS

Low levels of physical exercise and high frequency of migraine has been reported in several large population-based studies. In experimental studies exercise has been reported as a trigger factor for migraine as well as migraine prophylaxis. Possible mechanisms for how exercise may trigger migraine attacks, include acute release of neuropeptides such as calcitonin gene-related peptide or alternation of hypocretin or lactate metabolism. Mechanisms for migraine prevention by exercise may include increased beta-endorphin, endocannabinoid and brain-derived neurotrophic factor levers in plasma after exercise.

CONCLUSION

In conclusion, it seems that although exercise can trigger migraine attacks, regular exercise may have prophylactic effect on migraine frequency. This is most likely due to an altered migraine triggering threshold in persons who exercise regularly. However, the frequency and intensity of exercise that is required is still an open question, which should be addressed in future studies to delineate an evidence-based exercise program to prevent migraine in sufferers.

Characterization of dural afferent neurons innervating cranial blood vessels within the dura in rats

Dural afferent neurons are implicated in primary headaches including migraine. Although a significant portion of primary afferent neurons innervating the dura are myelinated A-type neurons, previous electrophysiological studies have primarily characterized the functional properties of small-sized C-type sensory neurons. Here we show the functional characterization of dural afferent neurons identified with the fluorescent dye DiI. DiI-positive neurons were divided into three types: small-, medium-, and large-sized neurons, based on their diameter, area, and membrane capacitance. The immunoreactivity of NF200, a marker of A-type myelinated neurons, was detected in most large-sized, but it was also present in a limited number of small- and medium-sized DiI-positive neurons. Capsaicin, a transient receptor potential vanilloid 1 agonist, induced the membrane currents in most small- and medium-sized neurons, but not in large-sized DiI-positive neurons. Tetrodotoxin-resistant Na⁺ channels were expressed in almost all types of DiI-positive neurons. Mechanosensitive currents were detected from a majority of large-sized, and to a lesser extent, small- and medium-sized DiI-positive neurons. The results suggest that most dural afferent neurons are nociceptive, e.g., polymodal C-type for small- and medium-sized neurons, and high-threshold nociceptive A-type mechanoreceptors for large-sized neurons. We also found that DiI-positive neurons differed with respect to passive and active membrane properties, and that sumatriptan, a representative drug used for the acute treatment of migraine attack, inhibited voltage-gated Ca²⁺ currents in all types of DiI-positive neurons. The present results showing the nociceptive properties of dural afferent neurons would contribute to understand the pathophysiology of primary headaches.

Clinical Features of Headache in Patients With Diagnosis of Definite Vestibular Migraine: The VM-Phenotypes Projects

Migraine is a common neurological disorder characterized by episodic headaches with specific features, presenting familial aggregation. Migraine is associated with episodic vertigo, named Vestibular Migraine (VM) whose diagnosis mainly rely on clinical history showing a temporary association of symptoms. Some patient refers symptoms occurring in pediatric age, defined "episodic symptoms which may be associated with migraine." The aim of this cross sectional observational study was to assess migraine-related clinical features in VM subjects. For the purpose, 279 patients were recruited in different centers in Europe; data were collected by a senior neurologist or ENT specialist through a structured questionnaire. The age of onset of migraine was 21.8 ± 9. The duration of headaches was lower than 24 h in 79.1% of cases. Symptoms accompanying migrainous headaches were, in order of frequency, nausea (79.9%), phonophobia (54.5%), photophobia (53.8%), vomiting (29%), lightheadedness (21.1%). Visual or other auras were reported by 25.4% of subjects. A familial aggregation was referred by 67.4%, while migraine precursors were reported by 52.3% of subjects. Patients reporting nausea and vomiting during headaches more frequently experienced the same symptoms during vertigo. Comparing our results in VM subjects with previously published papers in migraine sufferers, our patients presented a lower duration of headaches and a higher rate of familial aggregation; moreover some common characters were observed in headache and vertigo attacks for accompanying symptoms like nausea and vomiting and clustering of attacks.

Optical Coherence Tomography in Patients with Chronic Migraine: Literature Review and Update

Migraine is a chronic disease characterized by unilateral, pulsating, and often moderate-to-severe recurrent episodes of headache with nausea and vomiting. It affects approximately 15% of the general population, yet the underlying pathophysiological mechanisms are not fully understood. Optical coherence tomography (OCT) is a safe and reproducible diagnostic technique that utilizes infrared wavelengths and has a sensitivity of 8–10 μm. It can be used to measure thinning of the retinal nerve fiber layer (RNFL) in some neurological disorders. Although ophthalmologists are often the first specialists to examine patients with migraine, few studies have addressed the involvement of the optic nerve and retino-choroidal structures in this group. We reviewed the literature on the etiological and pathological mechanisms of migraine and the relationship between recurrent constriction of cerebral and retrobulbar vessels and ischemic damage to the optic nerve, retina, and choroid. We also assessed the role of OCT for measuring peripapillary RNFL thickness and macular and choroidal changes in migraine patients. There is considerable evidence of cerebral and retrobulbar vascular involvement in the etiology of migraine. Transitory and recurrent constriction of the retinal and ciliary arteries may cause ischemic damage to the optic nerve, retina, and choroid in patients with migraine. OCT to assess the thickness of the peripapillary RNFL, macula, and choroid might increase our understanding of the pathophysiology of migraine and facilitate diagnosis of retino-choroidal compromise and follow-up of therapy in migraine patients. Future studies should determine the usefulness of OCT findings as a biomarker of migraine.

The Use of Cannabis for Headache Disorders

Headache disorders are common, debilitating, and, in many cases, inadequately managed by existing treatments. Although clinical trials of cannabis for neuropathic pain have shown promising results, there has been limited research on its use, specifically for headache disorders. This review considers historical prescription practices, summarizes the existing reports on the use of cannabis for headache, and examines the preclinical literature exploring the role of exogenous and endogenous cannabinoids to alter headache pathophysiology. Currently, there is not enough evidence from well-designed clinical trials to support the use of cannabis for headache, but there are sufficient anecdotal and preliminary results, as well as plausible neurobiological mechanisms, to warrant properly designed clinical trials. Such trials are needed to determine short- and long-term efficacy for specific headache types, compatibility with existing treatments, optimal administration practices, as well as potential risks.

Anti-CGRP monoclonal antibodies in migraine: current perspectives

Migraine is a highly disabling neurological pain disorder in which management is frequently problematic. Most abortive and preventative treatments employed are classically non-specific, and their efficacy and safety and tolerability are often unsatisfactory. Mechanism-based therapies are, therefore, needed. Calcitonin gene-related peptide (CGRP) is recognized as crucial in the pathophysiology of migraine, and new compounds that target the peptide have been increasingly explored in recent years. First tested were CGRP receptor antagonists; they proved effective in acute migraine treatment in several trials, but were discontinued due to liver toxicity in long-term administration. Monoclonal antibodies against CGRP (LY2951742, ALD-403, and LBR-101/TEV-48125) or its receptor (AMG334) were subsequently developed. As reviewed in this study, numerous phase 1 and 2 trials and preliminary results of phase 3 trials have shown a good safety/tolerability profile and efficacy in migraine prevention, especially in high frequent episodic and chronic forms. Being macromolecules, these mAbs are not suitable for oral administration; however, their intravenous or subcutaneous delivery can be performed at relatively low frequency-every month or even quarterly-which enhances patients' compliance. Although not all migraineurs respond to this treatment, and longer administration periods will be needed to assess long-term effects, the results so far obtained are extraordinarily promising. The future introduction of mAbs on the market will probably represent a turning point for prevention similar to that represented by triptans for abortive treatment in migraine.

Clinical Benefits of Early Triptan Therapy for Migraine

The introduction of the triptans brought advances in achieving complete and sustained pain resolution in migraine patients, compared with non-migraine-specific treatments. However, sustained pain-free rates for triptans recorded in many clinical trials are still relatively low. This may be due to study participants being treated late into the attack, when pain is already moderate or severe. Studies with almotriptan have shown that efficacy is enhanced when treatment is given early in a migraine attack while pain is still mild, compared with later administration when pain intensity is greater. Developments in our understanding of migraine pathophysiology provide a rationale for this phenomenon, with improved efficacy seen when abortive treatment is administered before central sensitization develops. A limited window of therapeutic opportunity exists early in an attack to improve the outcome of triptan treatment. Early intervention is recommended to avoid the significant pain and disability commonly associated with moderate or severe migraine.

What Do Patients Want from Acute Migraine Treatment?

Clinical observations have shown that migraine is a progressive disorder, both within an acute attack, and within the disease itself. Rates of diagnosis for migraine have increased in the last decade, but more than half of migraineurs remain undiagnosed. Patient expectations of migraine therapies have also increased (patients require rapid and sustained pain relief with a treatment that has good tolerability), and can differ greatly from those of physicians. Management decisions should be made with these expectations in mind, to enhance patient outcomes and compliance with treatment. Improved understanding of acute migraine attack pathophysiology has led to the strategy of early treatment to modify both the progression of the current attack and, potentially, the progression of the disease itself in the individual. The triptans are effective acute migraine therapies. Each agent has its own distinct profile of efficacy and tolerability, enabling individualization of treatment.

Increased migraine risk in osteoporosis patients: a nationwide population-based study

BACKGROUND

Osteoporosis and migraine are both important public health problems and may have overlapping pathophysiological mechanisms. The aim of this study was to use a Taiwanese population-based dataset to assess migraine risk in osteoporosis patients.

METHODS

The Taiwan National Health Insurance Research Database was used to analyse data for 40,672 patients aged ≥20 years who had been diagnosed with osteoporosis during 1996-2010. An additional 40,672 age-matched patients without osteoporosis were randomly selected as the non-osteoporosis group. The relationship between osteoporosis and migraine risk was estimated using Cox proportional hazard regression models.

RESULTS

During the follow-up period, 1110 patients with osteoporosis and 750 patients without osteoporosis developed migraine. After controlling for covariates, the overall incidence of migraine was 1.37-fold higher in the osteoporosis group than in the non-osteoporosis group (3.72 vs. 1.24 per 1000 person-years, respectively). Migraine risk factors included high Charlson Comorbidity Index score, female gender, hypertension, depression, asthma, allergic rhinitis, obesity, and tobacco use disorder.

CONCLUSIONS

Our results indicate that patients with a history of osteoporosis had a higher risk of migraine.

Exteroceptive Suppression of Masseter Muscle Activity in Juvenile Migraineurs

The second exteroceptive suppression period (ES2) of masseter or temporalis muscle activity may be reduced in adults with chronic tension-type headache. In adults with migraine, ES2 was found normal or tended to be protracted. To date, no studies on exteroceptive suppression in children and adolescents with headaches have been published. We investigated the exteroceptive suppression of masseter muscle activity in 14 migraineurs and 19 controls between 6 and 18 years of age. It was elicited by electrical stimulation at the labial commissure. No differences were found regarding the first suppression period, but ES2 was significantly longer in the migraine group than in controls. The results of the migraine group suggest overactivity of the interneurons of the reflex loop due to impaired inhibitory control from superior antinociceptive systems already at the beginning of this headache disorder.

Autonomous control of cardiovascular reactivity in patients with episodic and chronic forms of migraine

BACKGROUND

The autonomous cardiovascular control can contribute to progression of migraine. However, current data on cardiovascular reactivity in migraine, especially severe forms, are essentially contradictory. The main aim of this study was to compare the autonomous regulation of circulation in patients with episodic and chronic migraine and healthy subjects.

METHODS

Seventy three migraine patients (mean age 35 ± 10) including episodic migraine (51 patients, 4-14 headache days/months) and chronic migraine (22 patients, ≥15 headache days/month) along with age-match control (71 healthy voluntaries) were examined. The autonomic regulation of circulation was examined with the tilt-table test, a deep breathing and Valsalva Maneuver, handgrip test, cold-stress vasoconstriction, arterial baroreflex and blood pressure variability.

RESULTS

The changes in heart rate induced by deep breathing, Valsalva Maneuver, and blood pressure in tilt-table test in patients with migraine did not differ from the control group. In contrast, the values of cold-stress-vasoconstriction forearm blood-flow reactivity (p <0.001), the increase in diastolic blood pressure in handgrip test (p <0.001), mean blood pressure in the late stage of the second phase of Valsalva Maneuver (p <0.001) and blood pressure variability (p <0.005) were all higher in patients with migraine than in the control group.

CONCLUSION

Thus, both episodic and chronic migraine are associated with significant disturbances in autonomous control resulting in enhanced vascular reactivity whereas the cardiac regulation remains largely unchanged.

Is Retinal Nerve Fiber Layer Thickness Change Related to Headache Lateralization in Migraine?

PURPOSE

To evaluate retinal nerve fiber layer (RNFL) thickness in migraine patients with unilateral headache.

METHODS

A total of 58 patients diagnosed with migraine headache consistently occurring on the same side and 58 age- and sex-matched healthy subjects were evaluated in this cross-sectional study. RNFL thickness was measured using spectral-domain optical coherence tomography, and the side with the headache was compared with the contralateral side as well as with the results of healthy subjects.

RESULTS

The mean patient age was 33.05 ± 8.83 years, and that of the healthy subjects was 31.44 ± 8.64 years (p = 0.32). The mean duration of disease was 10.29 ± 9.03 years. The average and nasal RNFL thicknesses were significantly thinner on the side of headache and on the contralateral side compared to control eyes (p < 0.05, for all). Thinning was higher on the side of the headache compared to the contralateral side; however, this difference was not statistically significant.

CONCLUSIONS

The RNFL thicknesses were thinner on the side of the headache compared to the contralateral side in the migraine patients with unilateral headache, but this difference was not statistically significant.

Migraine headache and bipolar disorder comorbidity: A systematic review of the literature and clinical implications

BACKGROUND AND AIMS

Psychiatric disorders, e.g., depression, are often comorbid with, and can complicate the treatment of, patients with migraine headache. Although empirical work has increasingly focused on the association between migraine and bipolar disorder, this topic has received little attention in the pain literature. Bipolar disorder is a chronic and recurrent mood disorder characterized by cyclic occurrence of elevated (i.e., manic or hypomanic) and depressed mood states. Bipolar I disorder is diagnosed when patients present with at least one abnormally and persistently elevated manic episode; bipolar II disorder is characterized by the presence of hypomanic episodes. Bipolar disorder warrants attention as depressive phases of the disorder can prevail and are often misconstrued by the unwary clinician as unipolar depression. However, treatment for bipolar disorder is distinct from that of unipolar depression and use of antidepressants, which are often invoked in migraine prophylaxis as well as the treatment of depression, may precipitate significant mood changes among bipolar disorder patients. A systematic review of the literature addressing the co-occurrence of bipolar disorder and migraine was conducted. The treatment of dually affected patients is also discussed.

METHODS

In order to review the literature to date on migraine and bipolar disorder co-occurrence, a comprehensive search of MEDLINE, EMBASE, PubMed, PsycINFO, Web of Science, and CINAHL for clinic-based and epidemiological studies was conducted using terms related to migraine and bipolar disorder. Studies were selected for review if they included subjects meeting validated diagnostic criteria for bipolar disorder as well as migraine headache and if a quantitative description of prevalence rates of comorbid bipolar disorder and migraine were reported. Weighted means of the prevalence rates were calculated to compare with general epidemiological prevalence trends for migraine and bipolar disorder, respectively.

RESULTS

Eleven studies met inclusion criteria. Although findings were constrained by methodological limitations and several low quality studies, clinic- and epidemiological cross-sectional investigations demonstrated a high rate of comorbidity between bipolar disorder and migraine. The weighted mean prevalence rate for migraine headache among bipolar disorder patients was 30.7%; for bipolar disorder among migraineurs, the weighted mean prevalence rates were 9% and 5.9% in clinic-based and epidemiological studies, respectively. The association between bipolar disorder and migraine was most notable among women and patients with the bipolar II disorder subtype.

CONCLUSIONS

High rates of comorbidity exist between migraine and bipolar disorder, exceeding estimated prevalence rates for those conditions in the general population. Comorbidity may portend a more serious clinical course for dually afflicted individuals.

IMPLICATIONS

Clinicians need to structure treatment approaches to address concurrent migraine and bipolar disorder in dually afflicted individuals. Although further evidence-based investigation is warranted to inform optimal treatment approaches for both conditions concurrently, anticonvulsants (e.g., valproate, lamotrigine and topiramate); atypical antipsychotics (e.g., olanzapine or quetiapine); and calcium channel blockers (e.g., verapamil) may be considered.

The Cortical Hyperexcitability Index (CHi): a new measure for quantifying correlates of visually driven cortical hyperexcitability

INTRODUCTION

Aberrations of visual experience, including visual hallucinations and visual distortions, are known to be associated with increased cortical hyperexcitability. As a consequence, the presence, intensity and frequency of certain experiences may well be indicative of an underlying increase in cortical hyperexcitability.

METHODS

The current study presents a new proxy measure of cortical hyperexcitability, the Cortical Hyperexcitability Index (CHi). Two hundred and fifty healthy participants completed the CHi with the results subjected to exploratory factor analysis (EFA).

RESULTS

The EFA revealed a three-factor model as the most parsimonious solution. The three factors were defined as: (1) heightened visual sensitivity and discomfort; (2) negative aura-type visual aberrations; and (3) positive aura-type visual aberrations. The identification of three factors suggests that multiple mechanisms underlie the notion of cortical hyperexcitability, providing researchers with new and greater precision in delineating these underlying features.

CONCLUSIONS

The factorial structure of the CHi and the increased precision could aid the interpretation of findings from neuroscientific (i.e., brain imaging/stimulation) examinations of cortical processes underlying aberrant perceptions across a host of clinical, neurological and pathological conditions. As a consequence, the CHi is a useful and comprehensive proxy measure of cortical hyperexcitability with considerable scientific and clinical utility.

Prophylactic effects of asiaticoside-based standardized extract of Centella asiatica (L.) Urban leaves on experimental migraine: Involvement of 5HT1A/1B receptors

The present study aimed at evaluation of prophylactic efficacy and possible mechanisms of asiaticoside (AS) based standardized extract of Centella asiatica (L.) Urban leaves (INDCA) in animal models of migraine. The effects of oral and intranasal (i.n.) pretreatment of INDCA (acute and 7-days subacute) were evaluated against nitroglycerine (NTG, 10 mg·kg(-1), i.p.) and bradykinin (BK, 10 μg, intra-arterial) induced hyperalgesia in rats. Tail flick latencies (from 0 to 240 min) post-NTG treatment and the number of vocalizations post-BK treatment were recorded as a measure of hyperalgesia. Separate groups of rats for negative (Normal) and positive (sumatriptan, 42 mg·kg(-1), s.c.) controls were included. The interaction of INDCA with selective 5-HT1A, 5-HT1B, and 5-HT1D receptor antagonists (NAN-190, Isamoltane hemifumarate, and BRL-15572 respectively) against NTG-induced hyperalgesia was also evaluated. Acute and sub-acute pre-treatment of INDCA [10 and 30 mg·kg(-1) (oral) and 100 μg/rat (i.n.) showed significant anti-nociception activity, and reversal of the NTG-induced hyperalgesia and brain 5-HT concentration decline. Oral pre-treatment with INDCA (30 mg·kg(-1), 7 d) showed significant reduction in the number of vocalization. The anti-nociceptive effects of INDCA were blocked by 5-HT1A and 5-HT1B but not 5-HT1D receptor antagonists. In conclusion, INDCA demonstrated promising anti-nociceptive effects in animal models of migraine, probably through 5-HT1A/1B medicated action.