Migraine pathogenesis and state of pharmacological treatment options

Transdermal drug delivery of rizatriptan using microneedles array patch: preparation, characterization and ex-vivo/in-vivo study

Given the extensive first pass metabolism of rizatriptan in oral administration and its delayed absorption during a migraine attack as a result of gastric stasis, focus has been on transdermal delivery. The main purpose of this study is to prepare and assess transdermal formulation of rizatriptan, loaded on hydrogel microneedles delivery system, to avoid first pass metabolism and also improve its percutaneous permeation rate. Rizatriptan hydrogel microneedles were prepared using micromolding method and evaluated in terms of mechanical strength, encapsulation efficiency, permeation and in-vivo skin absorption. Different formulations of rizatriptan microneedles (F1-F5) were successfully prepared using different concentrations of carboxymethyl cellulose and gelatin type A. Rizatriptan hydrogel microneedles demonstrated favorable mechanical properties, including withstanding insertion forces, thereby enhancing its skin insertion ability. In permeation study, the percent cumulative drug released after 24 h ranged between 93.1-100% which means that microneedles were able to deliver the drug effectively. For in-vivo study, F3 formulation was selected due to its superior characteristics over other formulations as it exhibited the highest swelling capacity, and demonstrated favorable mechanical properties. Furthermore, F3 showcased the most controlled drug release over a 24-hour period. Relative bioavailability of F3 microneedles was 179.59% compared to oral administration based on the AUC0-24. The observed AUC0-24 in F3 microneedles was statistically significant and 1.80 times greater than that in oral administration. The higher rizatriptan level in the microneedle demonstrated adequate drug permeability through the rat skin, suggesting the potential of microneedles for enhanced therapeutic effectiveness.

Prospective Matched Case-Control Study of Over-Early P100 Wave Latency in Migraine with Aura

A sizable portion of the world's population suffers from migraines with aura. The purpose of this research is to describe the findings of a case-control study that was carried out to gain a better understanding of how migraine with aura manifests. The research looked at the P100 delay of the visual-evoked potential in both eyes of 92 healthy people and 44 patients who suffered from migraines with visual aura. All of the participants in the study were recruited from King Fahad University Hospital in Saudi Arabia. Both sets of people had the same ancestry and originated from the same location. Patients who suffered from migraines with aura exhibited a significantly shorter P100 delay in both eyes compared to healthy controls (p = 0.001), which is evidence that their early visual processing was distinct. In order to arrive at these findings, we compared people who suffer from migraines with aura to people who do not suffer from migraines and used them as subjects. These findings contribute to the ongoing attempts to bring the disease under control and provide vitally significant new information regarding the functioning of headaches with auras. The primary focus of study in the future should be on determining the nature of the connection between issues with early visual processing and headaches with aura.

Isolation and characterization of major degradants in dihydroergotamine injection

In this study, we report the systematic approach for characterization of two major degradant impurities, which are not listed in any compendia and were formed during the stability studies of Dihydroergotamine mesylate injection (DHE). An ion-pair UPLC chromatographic method was developed to quantify the related substances present in the DHE injection drug product. The same was used to monitor the impurity profiling during its stability. The two unknown impurities were observed at RRT about 0.08 (Impurity-1) and RRT about 0.80 (Impurity-5) and found to be significantly increasing on stability. Forced degradation studies revealed the nature of the impurity and conditions required for enriching them. A Mass compatible HPLC method was developed to quantify only these two impurities using 25% ammonia and formic acid in water. Their mass numbers were identified using LC MS/MS with triple quadruple mass spectrometer coupled with a HPLC. These two impurities were then isolated from enriched products using preparative HPLC. These impurities were then characterized using Mass and NMR analysis along with Q-TOF elemental analysis.

Trends in utilization and costs of migraine medications, 2017–2020

Objective

This study examines changes in utilization and costs trends associated with migraine medications.

Background

Migraine attacks are a burden to many patients. There are many pharmacotherapy options available with newer migraine drug classes entering the market in the past decade. Little is known about the use, associated costs, and the impact of the newer agents.

Methods

This retrospective, cross-sectional study examined 2017–2020 administrative claims from a large national pharmacy benefits manager. Patients aged ≥ 18 years enrolled in commercial, Medicare, Medicaid, or health insurance exchange insurance plans who filled ≥ 2 prescription claims for triptans, ergotamines, isometheptenes, gepants, ditans, and CGRP mABs were included. A two-sample t-test was conducted to estimate whether differences in mean utilization and costs between 2017 and 2020 were statistically significant for migraine drug classes, except for CGRP mABs, which were estimated between 2018 and 2020.

Results

The sample ranged from 161,369 (2017) to 240,330 (2020) patients. 84.5% (n = 203,110; 2020) of patients were women. The number of 30-day adjusted prescription fills for prophylaxis remained stable over the four-year period, except for CGRP mABs, which increased from 0.5% (n = 0.007; 2018) to 5.3% (n = 0.075; 2020). Antiepileptics, antidepressants and beta blockers were the most common prophylaxes, while triptans, non-steroidal anti-inflammatory drugs/non-narcotic analgesics and opioids were the most common treatments utilized. CGRP mABs were the most expensive, while utilization of triptans were the highest. CGRP mABs had the largest increase in utilization (177.5%) and costs (166.3%) PPPM in 2020 ($291.17) compared to 2018 ($109.35), the year they were first available (p < 0.001). Between 2018 and 2020, costs increased overall and for commercial and Medicare enrollees, but remained unchanged for Medicaid and HIX members.

Conclusion

Our study demonstrates a shift in migraine medication utilization from 2017–2020, where increased use of CGRP mABs had a significant contribution to increased costs. These increased pharmacy costs must be weighed against the improved tolerability of these agents likely resulting in other healthcare and indirect cost savings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01476-y.

Intercritical photophobia in the migrainous patient. Proposal for diagnostic criteria

INTRODUCTION

Photophobia is a symptom of abnormal light intolerance without pain sensation that requires an anamnesis and an examination to diagnose an underlying etiology.

BASIC PROCEDURE

This article focuses on 30 clinical cases with isolated intense photophobia and on the review of the literature.

OBJECTIVE

The purpose of this article is to establish diagnostic criteria for photophobia.

RESULTS

The etiology of photophobia appears to be at the level of the intrinsically photosensitive retinal ganglion cells known as melanopsin cells and at a neurochemical level mediated by calcitonin-related peptide and the pituitary activating peptide cyclase.

CONCLUSION

The treatment of photophobia could consist of monoclonal antibodies against calcitonin-related peptide and/or pituitary activating peptide cyclase.

The Association Between Blood Pressure and Headache in Postmenopausal Women: A Prospective Hospital-Based Study

Background

Headache is the most frequent condition for outpatient patients because of neurological problems, but little is known about predisposing and enabling factors for headache patients.

Aim

To investigate the association between blood pressure (BP) and headache in postmenopausal women.

Methods

The postmenopausal women who were admitted to our hospital from January 2015 to December 2019 were screening according to the criteria. Their systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP) were assessed and the information of age, body mass index, smoking status, caffeine consumption, cholesterol levels, and daily alcohol use were collected. Multiple logistic regression model was established to evaluate the association between BP and headache.

Results

A total of 1571 postmenopausal women were included in the analysis, including 953 headache-free population and 618 headache participants during the studied periods. We found that increasing SBP and PP were associated with the lower occurrence of migraine, tension-type headache (TTH), probable migraine, and unclassified headache (P < 0.05). However, there was a negative association between DBP levels and the new occurrence of overall headache, but we did not find any relations of DBP with any subtypes of headache.

Conclusion

There were negative associations of SBP and PP with new occurrence of headache, especially migraine and TTH, but there is no relationship between DBP and the subsequent development of headache.

Intercritical photophobia in the migraineous patient. Proposal for diagnostic criteria

INTRODUCTION

Photophobia is a symptom of abnormal light intolerance without pain sensation that requires an anamnesis and an examination to diagnose an underlying etiology.

BASIC PROCEDURE

This article focuses on 30 clinical cases with isolated intense photophobia and on the review of the literature.

OBJECTIVE

The purpose of this article is to establish diagnostic criteria for photophobia.

RESULTS

The etiology of photophobia appears to be at the level of the intrinsically photosensitive retinal ganglion cells known as melanopsin cells and at a neurochemical level mediated by calcitonin-related peptide and the pituitary activating peptide cyclase.

CONCLUSION

The treatment of photophobia could consist of monoclonal antibodies against calcitonin-related peptide and/or pituitary activating peptide cyclase.

Association of dietary diversity score (DDS) and migraine headache severity among women

BACKGROUND AND OBJECTIVES

Migraine is an episodic disorder that is characterized by unilateral headache lasting 4-72 h along with certain associated features. Modifying dietary habits have been considered an appropriate therapeutic approach in these patients. This study was designed to examine the association between dietary diversity score (DDS) and severity, frequency, and duration of migraine attacks.

METHODS AND MATERIALS

The present study was conducted using a cross-sectional design on 256 women 18-50 years old referred to neurology clinics for the first time. After the diagnosis of migraine by a neurologist, the data related to anthropometric measures and dietary intake (147-item semi-quantitative food frequency questionnaire) were collected. To assess migraine severity, the migraine disability assessment questionnaire (MIDAS), visual analog scale (VAS), and a 30-day headache diary were used. Multinomial logistic regression was used to evaluate the association between DDS and migraine severity. The age, physical activity, BMI, and job were considered confounding variables in regression model. Data were analyzed using SPSS software and P values < 0.05 considered statistically significant.

RESULTS

Totally, 256 subjects participated in the present study with mean age, height, weight, and BMI of 34.28 ± 7.88 years, 161.78 ± 5.18 cm, 69.25 ± 13.06 kg, and 26.46 ± 4.89 kg/m2, respectively. Subjects with higher DDS had a lower waist circumference (P = 0.01). There was no association between DDS and other anthropometric measures and demographic characteristics (P > 0.05). In the crude model of logistic regression, participants with lower DDS had higher odds of more pain severity (OR = 2.30; 95% CI = 1.28, 4.12; P = 0.005), migraine disability (OR = 2.66; 95% CI = 1.51, 4.69; P = 0.001), and headache duration (OR = 2.32; CI = 1.22, 4.40; P = 0.01) compared to reference group. No association was found between headache frequency and DDS. Adjusting for the effect of confounding variables did not change the significant association.

CONCLUSION

DDS was inversely associated with migraine disability, pain severity, and headache frequency. Additional studies are needed to replicate these findings and to explore mechanisms that mediate the association between DDS and migraine attacks.

Neuropeptide changes in an improved migraine model with repeat stimulations

Migraine is a medical condition with a severe recursive headache. The activation of the trigeminovascular system is an important mechanism. The neuropeptide calcitonin gene-related peptide (CGRP) plays a crucial role in the pathogenesis of migraine. Several other neuropeptides are also involved; however, their roles in migraine remain unclear. In this study, using a rat model of migraine induced by electrical stimulation of the trigeminal ganglia (TG) and an improved version induced with repeated stimulation, we observed the dynamic changes of these peptides in TG and blood. We demonstrated that the expression of CGRP, pituitary adenylate cyclase activating polypeptide (PACAP), neuropeptide Y (NPY), vasoactive intestinal peptide, and nociceptin in TG was significantly elevated and peaked at different time points after a single stimulation. Their levels in the blood plasma were significantly increased at 12 h after stimulation. The peptides were further elevated with repeated stimulation. The improved rat model of migraine with repeated stimulation of TG resulted in a more pronounced elevation of CGRP, PACAP, and NPY. Thus, the dynamic changes in neuropeptides after stimulation suggest that these neuropeptides may play an important role in the pathogenesis of migraine. Additionally, the migraine model with repetitive stimulation would be a novel model for future research.

Going Deep into Synaptic Vesicle Machinery Genes and Migraine Susceptibility - A Case-Control Association Study

OBJECTIVE

A number of observations, including among our study population, have implicated variants in the syntaxin-1A, a component of the synaptic vesicles, in migraine susceptibility. Therefore, we hypothesize that variants in other components of the vesicle machinery are involved in migraine.

BACKGROUND

Migraine is a common and complex neurologic disorder that affects approximately 15-18% of the general population. The exact cause of migraine is unknown; however, genetic studies have made possible substantial progress toward the identification of underlying molecular pathways. Neurotransmitters have been for long considered to have a key role in migraine pathophysiology; so we investigated common variants in genes involved in the synaptic vesicle machinery and their impact in migraine susceptibility.

METHODS

We performed a case-control study comprising 188 unrelated patients with headache and 286 healthy controls in a population from the north of Portugal. Benefiting from the presence of linkage disequilibrium, we selected and genotyped 119 tagging single-nucleotide polymorphisms in 18 genes.

RESULTS

We found significant associations between single-nucleotide variants and migraine in 7 genes, SYN1, SYN2, SNAP25, VAMP2, STXBP1, STXBP5, and UNC13A, either conferring an increased risk or protection of migraine. Due to SYN1 X-chromosomal location, we performed the statistical analysis separated by gender and, in the female group, the C allele of rs5906435 increased the risk for migraine susceptibility (P = .021; OR = 1.69; 95% CI: 1.21-2.34). In contrast, the TT genotype of the same variant emerged as a potential protective factor (P = .003; OR = 0.45; 95% CI: 0.27-0.74). The SYN2 analysis supported the rs3773364's G allele (P = .014) as a risk factor for migraine, and although not statistically significant after correction, the AG genotype (P = .006; OR = 1.86; 95% CI: 1.20-2.90) reinforced the allelic findings. Additionally, we found the SNAP25-rs363039's CT genotype (P = .001; OR = 2.14; 95% CI: 1.36-3.34), the STXBP5-rs1765028's T allele (P = .041; OR = 1.46; 95% CI: 1.13-1.90), and the UNC13B-rs7851161's TT genotype (P = .001; OR = 2.14; 95% CI: 1.36-3.34) as statistically significant risk factors for migraine liability. VAMP2-rs1150's G allele revealed a risk association to migraine, not statistically significant after correction (P = .068). Additionally, we found haplotypes in SYN1, SYN2, STXBP1, and UNC13B to be associated with migraine.

CONCLUSIONS

Overall, this study provides a new insight into migraine liability, identifying possible starting points for functional studies.

Effect of propranolol with and without rosuvastatin on migraine attacks: a triple blind randomized clinical trial

Aim: To investigate the effect of rosuvastatin in combination with propranolol in reducing migraine attacks. Patients & methods: In a clinical trial study with census method, 120 patients with migraine headache were included. Patients were randomly assigned (using block randomization) to either propranolol (10 mg twice a day) with rosuvastatin (10 mg daily; intervention group [n = 60]) or propranolol (10 mg twice a day) with placebo (control [n = 60]). Results: The numbers of attacks were significantly decreased in the intervention group at the end of second, third and fourth weeks from the beginning of the intervention (p < 0.05). Conclusion: In patients with migraine, concomitant administration of propranolol (10 mg twice a day) and rosuvastatin (10 mg daily) is effective in reducing migraine attacks.

Cortical potentiation induced by calcitonin gene-related peptide (CGRP) in the insular cortex of adult mice

Recent studies demonstrate that calcitonin gene-related peptide (CGRP) plays critical roles in migraine. Immunohistochemistry and in situ hybridization studies have shown that CGRP and its receptors are expressed in cortical areas that are critical for pain perception including the anterior cingulate cortex (ACC) and insular cortex (IC). Recent studies reported that CGRP enhanced excitatory transmission in the ACC. However, little is known about the possible effect of CGRP on excitatory transmission in the IC. In the present study, we investigated the role of CGRP on synaptic transmission in the IC slices of adult male mice. Bath application of CGRP produced dose-dependent potentiation of evoked excitatory postsynaptic currents (eEPSCs). This potentiation was NMDA receptor (NMDAR) independent. After application of CGRP1 receptor antagonist CGRP_8–37 or BIBN 4096, CGRP produced potentiation was significantly reduced. Paired-pulse facilitation was significantly decreased by CGRP, suggesting possible presynaptic mechanisms. Consistently, bath application of CGRP significantly increased the frequency of spontaneous and miniature excitatory postsynaptic currents (sEPSCs and mEPSCs). By contrast, amplitudes of sEPSCs and mEPSCs were not significantly affected. Finally, adenylyl cyclase subtype 1 (AC1) and protein kinase A (PKA) are critical for CGRP-produced potentiation, since both selective AC1 inhibitor NB001 and the PKA inhibitor KT5720 completely blocked the potentiation. Our results provide direct evidence that CGRP contributes to synaptic potentiation in the IC, and the AC1 inhibitor NB001 may be beneficial for the treatment of migraine in the future.

Potential Protective Mechanisms of Ketone Bodies in Migraine Prevention

An increasing amount of evidence suggests that migraines are a response to a cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity. The ketogenic diet (KD), a diet mimicking fasting that leads to the elevation of ketone bodies (KBs), is a therapeutic intervention targeting cerebral metabolism that has recently shown great promise in the prevention of migraines. KBs are an alternative fuel source for the brain, and are thus likely able to circumvent some of the abnormalities in glucose metabolism and transport found in migraines. Recent research has shown that KBs-D-β-hydroxybutyrate in particular-are more than metabolites. As signalling molecules, they have the potential to positively influence other pathways commonly believed to be part of migraine pathophysiology, namely: mitochondrial functioning, oxidative stress, cerebral excitability, inflammation and the gut microbiome. This review will describe the mechanisms by which the presence of KBs, D-BHB in particular, could influence those migraine pathophysiological mechanisms. To this end, common abnormalities in migraines are summarised with a particular focus on clinical data, including phenotypic, biochemical, genetic and therapeutic studies. Experimental animal data will be discussed to elaborate on the potential therapeutic mechanisms of elevated KBs in migraine pathophysiology, with a particular focus on the actions of D-BHB. In complex diseases such as migraines, a therapy that can target multiple possible pathogenic pathways seems advantageous. Further research is needed to establish whether the absence/restriction of dietary carbohydrates, the presence of KBs, or both, are of primary importance for the migraine protective effects of the KD.

Efficacy and safety of exogenous ketone bodies for preventive treatment of migraine: A study protocol for a single-centred, randomised, placebo-controlled, double-blind crossover trial

Background

Currently available prophylactic migraine treatment options are limited and are associated with many, often intolerable, side-effects. Various lines of research suggest that abnormalities in energy metabolism are likely to be part of migraine pathophysiology. Previously, a ketogenic diet (KD) has been reported to lead to a drastic reduction in migraine frequency. An alternative method to a strict KD is inducing a mild nutritional ketosis (0.4–2 mmol/l) with exogenous ketogenic substances. The aim of this randomised, placebo-controlled, double-blind, crossover, single-centre trial is to demonstrate safety and superiority of beta-hydroxybutyrate (βHB) in mineral salt form over placebo in migraine prevention.

Methods/design

Forty-five episodic migraineurs (5–14 migraine days/months), with or without aura, aged between 18 and 65 years, will be recruited at headache clinics in Switzerland, Germany and Austria and via Internet announcements. After a 4-week baseline period, patients will be randomly allocated to one of the two trial arms and receive either the βHB mineral salt or placebo for 12 weeks. This will be followed by a 4-week wash-out period, a subsequent second baseline period and, finally, another 12-week intervention with the alternative treatment. Co-medication with triptans (10 days per months) or analgesics (14 days per months) is permitted. The primary outcome is the mean change from baseline in the number of migraine days (meeting International Classification of Headache Disorders version 3 criteria) during the last 4 weeks of intervention compared to placebo. Secondary endpoints include mean changes in headache days of any severity, acute migraine medication use, migraine intensity and migraine and headache-related disability. Exploratory outcomes are (in addition to routine laboratory analysis) genetic profiling and expression analysis, oxidative and nitrosative stress, as well as serum cytokine analysis, and blood βHB and glucose analysis (pharmacokinetics).

Discussion

A crossover design was chosen as it greatly improves statistical power and participation rates, without increasing costs. To our knowledge this is the first RCT using βHB salts worldwide. If proven effective and safe, βHB might not only offer a new prophylactic treatment option for migraine patients, but might additionally pave the way for clinical trials assessing its use in related diseases.

Trial registration

ClinicalTrials.gov, NCT03132233. Registered on 27 April 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3120-7) contains supplementary material, which is available to authorized users.

Current Prophylactic Medications for Migraine and Their Potential Mechanisms of Action

A relatively high number of different medications is currently used for migraine prevention in clinical practice. Although these compounds were initially developed for other indications and differ in their mechanisms of action, some general themes can be identified from the mechanisms at play. Efficacious preventive drugs seem to either suppress excitatory nervous signaling via sodium and/or calcium receptors, facilitate GABAergic inhibition, reduce neuronal sensitization, block cortical spreading depression and/or reduce circulating levels of CGRP. We here review such mechanisms for the different compounds.

Rorschach Evaluation of Personality and Emotional Characteristics in Adolescents With Migraine Versus Epilepsy and Controls

The literature examining primary headache, including migraine, in adolescents, has pointed out the key role played by a wide range of psychiatric disorders in reducing the patients’ quality of life. Moreover, pioneering studies showed that preexisting personality characteristics, specific emotion regulation styles and psychological-psychiatric difficulties are likely to increase the risk of the onset, maintenance, and outcome of headache. Still personality issues in migraine have been poorly studied, in particular in children and adolescents. This study aims, therefore, to investigate the specific characteristics of personality, and in particular emotion regulation and coping strategies, in adolescent with migraine, comparing them with age-matched patients with idiopathic epilepsy and healthy adolescents. 52 adolescents (age: 11–17) were assessed using a multi-method test battery, which included a self-report questionnaire (the youth self-report), a proxy-report (child behavior checklist) along with a projective personality test, the Rorschach Test, administered and scored according to the Exner comprehensive system. The results showed specific personality characteristics in adolescents with migraine, revealing a marked difficulty in modulating and regulating affections through thoughts and reflections, resorting instead to impulsive acts and maladaptive coping strategies, thus revealing a vague and immature perception of reality. Differently from adolescents belonging to the general population, but similarly to patients with epilepsy, adolescents with migraine perceive a high situational stress, probably related to the condition of suffering from chronic disease. They have, therefore, a lower self-consideration and self-esteem along with a poorer insight regarding themselves as well as the relations with others. In line with previous findings, these preliminary results suggest the need for further research on ample samples, using also standardized projective test in order to better understand the pathogenesis of psychological difficulties in patients with migraine. As a clinical implication, the results seem to indicate that providing a psychological integrated approach can play a pivotal role in the assessment and treatment of adolescent with migraine, in order to improve the outcome and the quality of life of the young patients.

Photophobia in neurologic disorders

Photophobia is a common symptom seen in many neurologic disorders, however, its pathophysiology remains unclear. Even the term is ambiguous. In this paper, we review the epidemiology and clinical manifestations of photophobia in neurological disorders, including primary headache, blepharospasm, progressive supranuclear palsy, and traumatic brain injury, discuss the definition, etiology and pathogenesis, and summarize practical methods of diagnosis and treatment.

Distribution of CGRP and CGRP receptor components in the rat brain

BACKGROUND

Calcitonin gene-related peptide and its receptor, consisting of receptor activity-modifying protein 1 and calcitonin receptor-like receptor, are of considerable interest because of the role they play in migraine and recently developed migraine therapies.

METHODS

To better understand the function of this neuropeptide, we used immunohistochemistry to determine a detailed distribution of calcitonin gene-related peptide, receptor activity-modifying protein 1 and calcitonin receptor-like receptor in the rat brain in a region of 0.5-1.5 mm lateral to the midline. We found calcitonin gene-related peptide immunoreactivity in most of the neurons of the cerebral cortex, hippocampus, cerebellum, thalamic nuclei, hypothalamic nuclei and brainstem nuclei. In contrast, receptor activity-modifying protein 1 and calcitonin receptor-like receptor immunoreactivity were found almost exclusively in the neuronal processes in the investigated regions.

CONCLUSION

Overall, the degree of expression of calcitonin gene-related peptide and calcitonin gene-related peptide receptor components in the central nervous system is astonishingly complex and suggestive of many different brain functions, including a possible role in migraine. However, currently, the presence of calcitonin gene-related peptide and the nature of its receptors throughout the brain is an enigma yet to be solved.

Follow-up over 20 months confirms gains of online behavioural training in frequent episodic migraine

Aim This study examined the change over 20 months in 178 participants with frequent episodic migraine under adequate treatment as usual, who had completed online behavioural training (oBT) in migraine self-management either directly (group 1, n = 120) or after 10 months of watchful waiting (group 2, n = 58). Methods Participants completed questionnaires and an online headache diary and migraine monitor following the International Classification of Headache Disorders at T0 (baseline), T1 (post-training), T2 (6-month follow-up; extended baseline in group 2), T3 (post-training, group 2 only) and T4 (group 1: 16-month follow-up; group 2: 6-month follow-up). Statistical analyses were conducted on the observed data without imputation of missing observations. Results Both groups were highly comparable. The data over time revealed benefits in response to oBT, with significant between-group differences in the change achieved in the training episodes T2-T0 (group 1) and T4-T2 (group 2). Improved attack frequency ( M = -23%) was higher in participants with more (i.e. 4-6) attacks per month at baseline, and the effects of oBT were durable over 16 months of follow-up. Conclusions oBT is beneficial in frequent episodic migraine, which deserves special efforts in care. Self-management variants such as oBT reach patients easily and supplement these efforts with durable results.

A comparison of outcome of medical and surgical treatment of migraine headache: In 1 year follow-up

BACKGROUND

This study was designed to compare the efficacy of the medical treatment versus the surgical treatment approach to decompression of trigger point nerves in patients with migraine headaches.

MATERIALS AND METHODS

Fifty volunteers were randomly assigned to the medical treatment group (n = 25) or the surgical treatment group (n = 25) after examination by the team neurologist to ensure a diagnosis of migraine headache. All patients received botulinum toxin type A to confirm the trigger sites. The surgical treatment group underwent surgical deactivation of the trigger site(s). The medical treatment group underwent prophylactic pharmacologic interventions by the neurologist. Pretreatment and 12-month posttreatment migraine headache frequency, duration, and intensity were analyzed and compared to determine the success of the treatments.

RESULTS

Nineteen of the 25 patients (76%) in the surgical treatment group and 10 of the 25 patients (40%) in the medical treatment group experienced a successful outcome (at least a 50% decrease in migraine frequency, duration, or intensity) after 1 year from surgery. Surgical treatment had a significantly higher success rate than medical treatment (P < 0.001). Nine patients (36%) in the surgical treatment group and one patient (4%) in the medical treatment group experienced cessation of migraine headaches. The elimination rate was significantly higher in the surgical treatment group than in the medical treatment group (P < 0.001).

CONCLUSIONS

Based on the 1-year follow-up data, there is strong evidence that surgical manipulation of one or more migraine trigger sites can successfully eliminate or reduce the frequency, duration, and intensity of migraine headaches in a lasting manner.

Multi-frequency analysis of brain connectivity networks in migraineurs: a magnetoencephalography study

Background

Although alterations in resting-state neural network have been previously reported in migraine using functional MRI, whether this atypical neural network is frequency dependent remains unknown. The aim of this study was to investigate the alterations of the functional connectivity of neural network and their frequency specificity in migraineurs as compared with healthy controls by using magnetoencephalography (MEG) and concepts from graph theory.

Methods

Twenty-three episodic migraine patients with and without aura, during the interictal period, and 23 age- and gender-matched healthy controls at resting state with eye-closed were studied with MEG. Functional connectivity of neural network from low (0.1–1 Hz) to high (80–250 Hz) frequency ranges was analyzed with topographic patterns and quantified with graph theory.

Results

The topographic patterns of neural network showed that the migraineurs had significantly increased functional connectivity in the slow wave (0.1–1 Hz) band in the frontal area as compared with controls. Compared with the migraineurs without aura (MwoA), the migraineurs with aura (MwA) had significantly increased functional connectivity in the theta (4–8 Hz) band in the occipital area. Graph theory analysis revealed that the migraineurs had significantly increased connection strength in the slow wave (0.1–1 Hz) band, increased path length in the theta (4–8 Hz) and ripple (80–250 Hz) bands, and increased clustering coefficient in the slow wave (0.1–1 Hz) and theta (4–8 Hz) bands. The clinical characteristics had no significant correlation with interictal MEG parameters.

Conclusions

Results indicate that functional connectivity of neural network in migraine is significantly impaired in both low- and high-frequency ranges. The alteration of neural network may imply that migraine is associated with functional brain reorganization.

Is ciliary muscle affected in migraine patients with aura and without aura?

BACKGROUND

The aim of this study was to compare spherical equivalents (SE) and spherical equivalents with cycloplegic (CSE) values of migraine patients with and without visual aura, with those patients without migraine complaints.

MATERIAL/METHODS

We included patients over the age of 18 years, who had 20/20 uncorrected vision, and who did not have ocular pathology in their examination. The patients were divided into 3 groups: Group 1: 86 eyes of 43 migraine patients without aura, Group 2: 38 eyes of 19 migraine patients with aura, and Group 3: 60 eyes of 30 patients without migraine. Spherical equivalents and spherical equivalents with cycloplegic from the auto-refractometrical values of the patients were compared.

RESULTS

The mean age of the migraine and control patients was 34.2±8.3 and 33.6±10.8 years, respectively. Forty-three (69%) of 62 migraine patients had migraine without aura and 19 (31%) had migraine with aura. The right and left eyes of the patients were evaluated together and a significant correlation was found between the groups. To evaluate the impact of cycloplegia in patients, SE and CSE values were obtained and differences between these values were evaluated. It was found that the change in Group 2 patients was significantly lower than the change in Group 3 patients (p=0.024).

CONCLUSIONS

We found that the cycloplegic spherical equivalents values of our patients with aura were lower than control patients. We need further studies to reveal whether migraine with aura is the trigger or the result of those attacks.

Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) for the prevention of migraine in adults

BACKGROUND

This is an updated version of the original Cochrane review published in 2005 on selective serotonin reuptake inhibitors (SSRIs) for preventing migraine and tension-type headache. The original review has been split in two parts and this review now only regards migraine prevention. Another updated review is under development to cover tension-type headache.Migraine is a common disorder. The chronic forms are associated with disability and have a high economic impact. In view of discoveries about the role of serotonin and other neurotransmitters in pain mechanisms, selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) have been evaluated for the prevention of migraine.

OBJECTIVES

To determine the efficacy and tolerability of SSRIs and SNRIs compared to placebo and other active interventions in the prevention of episodic and chronic migraine in adults.

SEARCH METHODS

For the original review, we searched MEDLINE (1966 to January 2004), EMBASE (1994 to May 2003), the Cochrane Central Register of Controlled Trials (CENTRAL 2003, Issue 4), and Headache Quarterly (1990 to 2003). For this update, we applied a revised search strategy to reflect the broader type of intervention (SSRIs and SNRIs). We searched CENTRAL (2014, Issue 10), MEDLINE (1946 to November 2014), EMBASE (1980 to November 2014), and PsycINFO (1987 to November 2014). We also checked the reference lists of retrieved articles and searched trial registries for ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials comparing SSRIs or SNRIs with any type of control intervention in participants 18 years and older of either sex with migraine.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data (migraine frequency, index, intensity, and duration; use of symptomatic/analgesic medication; days off work; quality of life; mood improvement; cost-effectiveness; and adverse events) and assessed the risk of bias of trials. The primary outcome of this updated review is migraine frequency.

MAIN RESULTS

The original review included eight studies on migraine. Overall, we now include 11 studies on five SSRIs and one SNRI with a total of 585 participants. Six studies were placebo-controlled, four compared a SSRI or SNRI to amitriptyline, and one was a head-to-head comparison (escitalopram versus venlafaxine). Most studies had methodological or reporting shortcomings (or both): all studies were at unclear risk of selection and reporting bias. Follow-up rarely extended beyond three months. The lack of adequate power of most of the studies is also a major concern.Few studies explored the effect of SSRIs or SNRIs on migraine frequency, the primary endpoint. Two studies with unclear reporting compared SSRIs and SNRIs to placebo, suggesting a lack of evidence for a difference. Two studies compared SSRIs or SNRIs versus amitriptyline and found no evidence for a difference in terms of migraine frequency (standardised mean difference (SMD) 0.04, 95% confidence interval (CI) -0.72 to 0.80; I(2) = 72%), or other secondary outcomes such as migraine intensity and duration.SSRIs or SNRIs were generally more tolerable than tricyclics. However, the two groups did not differ in terms of the number of participants who withdrew due to adverse advents or for other reasons (one study, odds ratio (OR) 0.39, 95% CI 0.10 to 1.50 and OR 0.42, 95% CI 0.13 to 1.34).We did not find studies comparing SSRIs or SNRIs with pharmacological treatments other than antidepressants (e.g. antiepileptics and anti-hypertensives).

AUTHORS' CONCLUSIONS

Since the last version of this review, the new included studies have not added high quality evidence to support the use of SSRIs or venlafaxine as preventive drugs for migraine. There is no evidence to consider SSRIs or venlafaxine as more effective than placebo or amitriptyline in reducing migraine frequency, intensity, and duration over two to three months of treatment. No reliable information is available at longer-term follow-up. Our conclusion is that the use of SSRIs and SNRIs for migraine prophylaxis is not supported by evidence.

How spreading depolarization can be the pathophysiological correlate of both migraine aura and stroke

The term spreading depolarization describes a mechanism of abrupt, massive ion translocation between neurons and the interstitial space, which leads to a cytotoxic edema in the gray matter of the brain. In energy-compromised tissue, spreading depolarization is preceded by a nonspreading silencing (depression of spontaneous activity) because of a neuronal hyperpolarization. By contrast, in tissue that is not energy compromised, spreading depolarization is accompanied by a spreading silencing (spreading depression) of spontaneous activity caused by a depolarization block. It is assumed that the nonspreading silencing translates into the initial clinical symptoms of ischemic stroke and the spreading silencing (spreading depression) into the symptoms of migraine aura. In energy-compromised tissue, spreading depolarization facilitates neuronal death, whereas, in healthy tissue, it is relatively innocuous. Therapies targeting spreading depolarization in metabolically compromised tissue may potentially treat conditions of acute cerebral injury such as aneurysmal subarachnoid hemorrhage.

Effect of catheter ablation and periprocedural anticoagulation regimen on the clinical course of migraine in atrial fibrillation patients with or without pre-existent migraine: results from a prospective study

BACKGROUND

We examined the influence of catheter ablation and periprocedural anticoagulation regimen on trajectory of migraine in atrial fibrillation patients with or without migraine history.

METHODS AND RESULTS

Forty patients with (group 1: 64 ± 8 years; men 78%) and 85 (group 2: 61 ± 10 years; men 73%) without migraine history undergoing atrial fibrillation-ablation were enrolled. Migraine status and quality of life were evaluated using standardized questionnaires. Diffusion magnetic resonance imaging of brain was performed for all at pre and 24 hours post procedure. Catheter ablation was performed with (88, 70%) or without (37, 30%) continuous warfarin treatment. Fifty-four patients (11 and 43 from groups 1 and 2, respectively) had subtherapeutic international normalized ratio on procedure day. At 17 ± 5 months follow-up, from group 1, 25 (63%) reported no migraine, 10 (25%) had < 1, and 3 (8%) had 2 to 3 monthly symptoms. Intensity of pain decreased from baseline 7 (Q1-Q3, 4-8) to 2 (0-4) scale points at follow-up (P < 0.001) and duration of headache from median 8 (Q1-Q3, 4-15) to 0.5 (Q1-Q3, 0-2) hours (P < 0.001). Two patients from group 1 reported increased migraine severity and 2 from group 2 had new-onset migraine. Follow-up diffusion magnetic resonance imaging revealed new infarcts in 9.6% (12/125) patients; of which 11 had subtherapeutic preprocedural international normalized ratio on or off continuous warfarin. Quality of life improved significantly in patients with successful ablation, being more pronounced in group 1.

CONCLUSIONS

In most patients, migraine symptoms improved substantially after catheter ablation. Interestingly, the only cases of new migraine and aggravation of pre-existent headache had subtherapeutic international normalized ratio during the procedure and new cerebral infarcts.

Gene expression microarray analysis of the spinal trigeminal nucleus in a rat model of migraine with aura

Cortical spreading depression can trigger migraine with aura and activate the trigeminal vascular system. To examine gene expression profiles in the spinal trigeminal nucleus in rats following cortical spreading depression-induced migraine with aura, a rat model was established by injection of 1 M potassium chloride, which induced cortical spreading depression. DNA microarray analysis revealed that, compared with the control group, the cortical spreading depression group showed seven upregulated genes–myosin heavy chain 1/2, myosin light chain 1, myosin light chain (phosphorylatable, fast skeletal muscle), actin alpha 1, homeobox B8, carbonic anhydrase 3 and an unknown gene. Two genes were downregulated–RGD1563441 and an unknown gene. Real-time quantitative reverse transcription-PCR and bioinformatics analysis indicated that these genes are involved in motility, cell migration, CO₂/nitric oxide homeostasis and signal transduction.

Inhibitory effect of chronic oral treatment with fluoxetine on capsaicin-induced external carotid vasodilatation in anaesthetised dogs

Background

During migraine, capsaicin-sensitive trigeminal sensory nerves release calcitonin gene-related peptide (CGRP), resulting in cranial vasodilatation and central nociception. Moreover, 5-HT is involved in the pathophysiology of migraine and depression. Interestingly, some limited lines of evidence suggest that fluoxetine may be effective in migraine prophylaxis, but the underlying mechanisms are uncertain. Hence, this study investigated the canine external carotid vasodilator responses to capsaicin, α-CGRP and acetylcholine before and after acute and chronic oral treatment with fluoxetine.

Methods

Forty-eight vagosympathectomised male mongrel dogs were prepared to measure blood pressure, heart rate and external carotid blood flow. The thyroid artery was cannulated for infusions of agonists. In 16 of these dogs, a spinal cannula was inserted (C1–C3) for infusions of 5-HT.

Results

The external carotid vasodilator responses to capsaicin, α-CGRP and acetylcholine remained unaffected after intracarotid or i.v. fluoxetine. In contrast, the vasodilator responses to capsaicin, but not those to α-CGRP or acetylcholine, were inhibited after chronic oral treatment with fluoxetine (300 µg/kg; for 90 days) or intrathecal 5-HT.

Conclusions

Chronic oral fluoxetine inhibited capsaicin-induced external carotid vasodilatation, and this inhibition could partly explain its potential prophylactic antimigraine action.

Characteristics of posttraumatic headache following mild traumatic brain injury in military personnel in Iran

OBJECTIVES

The primary goal of this study was to evaluate the incidence and characteristics of posttraumatic headache attributed to mild brain injury in military personnel in Iran within a prospective and observational study design.

METHODS

A prospective observational descriptive study was conducted with a cohort of military personnel under military education during a 6-month period at the Military Education Center in Isfahan, Iran. 322 military personnel under education were selected randomly and were given a 13-item mild brain injury questionnaire accompanied with affective disorders and headache questionnaires and were reevaluated after a 3-month interval.

RESULTS

A total of 30 (9.3 %) of the 322 military personnel met criteria for a mild brain injury. Among them, 18 personnel (60 %) reported having headaches during the 3-month reevaluation. PTHs defined as headaches beginning within 1 week after a head trauma were present in 5.6 % of military personnel under study during 6 months. In total, 67 % of posttraumatic headaches (PTH) were classified as migrainous or possible migrainous features. Patients with affective disorders such as posttraumatic stress disorder and depression were at a higher risk for developing PTH following mild brain injury (p < 0.05). PTH did not relate to demographic factors such as age or type of trauma.

CONCLUSIONS

Posttraumatic headache attributed to mild brain injury is a common disorder in military personnel. Migrainous features are predominant among them in comparison with the general population. PTH is not related to a type of trauma, but has association with affective disorders.

Migraine with aura is associated with impaired colour vision: Results from the cross-sectional German DMKG headache study

BACKGROUND

Hypersensitivity to light, noise and odour are pivotal clinical characteristics of migraine associated with enhanced cortical excitability and dysfunctional habituation. However, little is known about the integrity of basic sensory functioning in migraine on a population-based level.

METHODS

A total of 129 participants with migraine (105 without aura, MwoA, 24 with aura, MA) and 522 healthy controls without headache 12 months prior to baseline were included from a sample of the DMKG study and underwent standardised clinical sensory testing of smell, taste, hearing and vision.

RESULTS

After adjustment for age, sex, smoking status and history of head injuries, the chance of impaired colour perception was significantly higher in MA compared to controls (odds ratio, OR=3.20; 95% CI=1.20-8.53) and MwoA (OR=3.62; 95% CI=1.31-9.97). Compared to MwoA, MA also had an increased chance of smell (OR=3.20; 95% CI=0.98-10.42) and taste (OR=2.58; 95% CI=0.90-7.40) impairment.

CONCLUSIONS

In this cross-sectional, population-based study on sensory functioning in migraine participants, colour vision was impaired interictally in MA compared to MwoA and controls.

Insights and advances in post-traumatic headache: research considerations

Despite the growing awareness of mild traumatic brain injury in military and civilian populations, understanding of the acute and chronic effects of concussion on central nervous system structure and function is limited. Even less is understood about the underpinnings of the cardinal postconcussive symptom, post-traumatic headache (PTH). Here, we review recent advances in PTH, with special emphasis on the migraine-like phenotype, the most disabling form. Considerations for future research in PTH are discussed, including diagnostic classification, and applications with advanced neuroimaging techniques, biomarkers, and treatments.

Is the migrainous brain normal outside of acute attacks? Lessons learned from psychophysical, neurochemical and functional neuroimaging studies

Migraine is a largely inherited disorder of the brain with recurrent head pain attacks. There is an increasing awareness, however, that the manifestation of migrainous biology is not restricted to such acute head pain attacks, but that migraine is rather a disorder with a continuous complex and broad sensory processing dysfunction in which normal sensory stimuli (somatosensory, visual, auditory and olfactory) are misinterpreted by the brain. This dysfunction is most prominent during attacks, but there are more and more evidences that the processing and perception of stimuli is abnormal also outside of attacks to a varying degree. In this topical review, we will summarize and discuss the current clinical, neurochemical and functional neuroimaging literature on this paradigm shift from a strictly episodic head pain disorder to migraine as a more general dysfunction of sensory processing.

Orofacial pain management: current perspectives

Some of the most prevalent and debilitating pain conditions arise from the structures innervated by the trigeminal system (head, face, masticatory musculature, temporomandibular joint and associated structures). Orofacial pain (OFP) can arise from different regions and etiologies. Temporomandibular disorders (TMD) are the most prevalent orofacial pain conditions for which patients seek treatment. Temporomandibular disorders include a number of clinical problems that involve the masticatory musculature, the temporomandibular joint (TMJ) or both. Trigeminal neuropathic pain conditions can arise from injury secondary to dental procedures, infection, neoplasias, or disease or dysfunction of the peripheral and/or central nervous system. Neurovascular disorders, such as primary headaches, can present as chronic orofacial pain, such as in the case of facial migraine, where the pain is localized in the second and third division of the trigeminal nerve. Together, these disorders of the trigeminal system impact the quality of life of the sufferer dramatically. A multidisciplinary pain management approach should be considered for the optimal treatment of orofacial pain disorders including both non-pharmacological and pharmacological modalities.

Clinical Predictors for Migraine in Patients Presenting With Nausea and/or Vomiting

Background/Aims

Many migraine patients develop nausea and/or vomiting (N/V) and are referred to gastroenterologists. This can lead to an inappropriate treatment and a delay of the correct diagnosis. We therefore aimed to identify predictors for migraine in patients presenting with N/V as well as headache.

Methods

A total of 407 patients who were first diagnosed with migraine at Samsung Medical Center, Seoul, Korea, in 2009 were analyzed. Among them, 261 patients had N/V (migraine with N/V group) and 146 did not (migraine without N/V group). Each patient was evaluated using a structured questionnaire.

Results

Migraine with N/V group was younger, comprised of more females, had more abnormal body mass index, less alcohol intake, more family history of migraine, higher attack severity, more stress association, more aggravation by physical activity, more abdominal pain, and more photophobia/phonophobia than migraine without N/V group. Multivariate analysis revealed that young age (age < 40 years vs. ≥ 40 years, odds ratio (OR), 2.128; 95% confidence interval (CI), 1.206-3.756; P = 0.009), female (OR, 2.703; 95% CI, 1.492-4.896; P = 0.001), family history of migraine (OR, 2.080; 95% CI, 1.169-3.700; P = 0.013), abdominal pain (OR, 4.452; 95% CI, 1.263-15.693; P = 0.020), and photophobia/phonophobia (OR, 2.296; 95% CI, 1.308-4.030; P = 0.004) were independent predictive factors associated with migraine in patients with N/V.

Conclusions

Because young age, female, family history of migraine, abdominal pain, and photophobia/phonophobia are associated with migraine in patients presenting with N/V as well as headache, physicians should have a high index of suspicion for migraine in N/V patients who belong to these categories.

Episodic migraines in children: limited evidence on preventive pharmacological treatments

The authors conducted a systematic literature review of preventive pharmacological treatments for episodic childhood migraines searching several databases through May 20, 2012. Episodic migraine prevention was examined in 24 publications of randomized controlled trials that enrolled 1578 children in 16 nonrandomized studies. Single randomized controlled trials provided low-strength evidence that propranolol would result in complete cessation of migraine attacks in 713 per 1000 children treated (95% confidence interval, 452-974); trazodone and nimodipine decreased migraine days, while topiramate, divalproex, and clonidine were no more effective than placebo in preventing migraines. Migraine prevention with multidisciplinary drug management was not sustained at 6 months. Divalproex resulted in treatment discontinuation due to adverse effects, and topiramate increased the risk of paresthesia, upper respiratory tract infection, and weight loss. Long-term preventive benefits and improvement in disability and quality of life are unknown. No studies examined quality of life or provided evidence for individualized treatment decisions.

Prodromal functioning of migraine patients relative to their interictal state--an ecological momentary assessment study

Smartphones were used in an online Ecological Momentary Assessment (EMA) design to test prodromal functioning relative to the interictal state in migraine patients. Eighty-seven participants completed an electronic diary 4 times daily during 3-6 weeks to monitor their migraine attacks. Twice daily the diary additionally included 16 multi-answer questions covering physical symptoms (30 items), cognitive-affective functioning (25 items) and external factors (25 items). Eight clustered prodromal features were identified in the current study: sensory sensitivity, pain/stiffness, fatigue, cognitive functioning, positive affect, negative affect, effort spent and stressors encountered. Per feature, individual change scores with interictal control days--excluding 24-hour post-attack recovery--were computed for six 12-hour pre-attack time windows covering three prodromal days. Linear mixed model (fixed-effect) analysis established significant increases in sensory sensitivity, pain/stiffness and fatigue, and a tendency for increased negative affect, in the 12 hours prior to the attack. Positive affect and cognitive functioning were impaired both in the 25-36 hour and--more strongly--in the 12-hour time window before the attack. No effects were found for effort spent and stressors encountered. Exploratory (random effect) analysis revealed significant individual differences in the change scores in sensory sensitivity, pain/stiffness, fatigue and negative affect. It is concluded that the prodromal change in migraine--relative to interictal functioning--predominantly exists within the last 12 hours before attack onset. Individual diversity is large, however. Future research should zoom in to identify prodrome development within the 12 pre-attack hours as well as to isolate individual patterns.

Biomarkers associated with migraine and their potential role in migraine management

OBJECTIVE

The focus of this review is to review potential diagnostic and therapeutic biomarkers associated with migraine.

BACKGROUND

Migraine headache is a common disease that affects millions of individuals worldwide. Although well-accepted diagnostic criteria exist for migraine, it is still a complex disorder that remains both underdiagnosed and misdiagnosed. The causes of migraine are likely a mix of genetic, epigenetic, and environmental factors that, together with the individual's life history, translate into the observed clinical heterogeneity. Inherent clinical heterogeneity is an obstacle in developing more effective treatments. The lack of appropriate biomarkers is also an impediment to developing more effective therapeutic/preventive approaches. Ultimately, biomarkers may facilitate the goal of individualized medicine by enabling clinicians to more accurately diagnose and treat migraine and other types of headache.

METHODS

A comprehensive review was conducted of PubMed citations containing the key word "marker" OR "biomarker" combined with "migraine" OR "headache." Other key words included "serum," "saliva," "cerebrospinal fluid," "genes," "blood," and "inflammation." The only restriction was English-language publication. The abstracts of all articles meeting these criteria were reviewed, and full text was retrieved and examined for relevant references.

RESULTS

Data from human studies have begun to identify genetic mutations/polymorphisms and altered levels of specific proinflammatory and neuromodulatory molecules that strongly correlate with migraine as well as symptom severity. Results from a smaller number of studies have identified parameters, such as the neuropeptide calcitonin gene-related peptide (CGRP), which are significantly associated with response to specific treatments for acute migraine attacks and prophylaxis. Epigenetic mechanisms may also be involved in the development of migraine, and understanding environmentally induced genetic changes associated with this disease may eventually guide the development of therapies capable of reversing these pathophysiological changes in gene function.

CONCLUSIONS

The understanding of the etiology of migraine is incomplete. Although the identification and validation of biomarkers has greatly advanced diagnostic precision and measures of therapeutic efficacy in other diseases, there are no currently accepted biomarkers for chronic or episodic migraine. However, the continued investigation and identification of genetic, epigenetic, and molecular biomarkers is likely to facilitate the goal of individualizing medicine by enabling clinicians to more accurately diagnose and treat migraine and other headache disorders.

New onset migraine with aura after treatment initiation with ivabradine

Background

Migraine with aura is a complex neurological disorder modeled in animals by cortical spreading depression. It is less usual to find complete animal models for the disease so any opportunity to test a human effect back at the bench is welcome.

Findings

We report the case of a 24 year old woman who developed new onset episodic migraine with visual aura shortly after treatment initiation with the If ion channel blocker ivabradine for frequency control in hypertrophic cardiomyopathy. We studied whether ivabradine could alter cortical spreading depression in a suitable animal model. Sixteen rats received either ivabradine or saline, and the number of depolarization shifts and blood flow changes induced by cortical spreading depression were measured in both groups. No significant differences between the ivabradine and saline group were detected.

Conclusions

Ivabradine is an interesting substance since it is known to produce migraine-like phosphenes frequently and the patient we report developed de novo migraine with aura. However, we were unable to demonstrate that the drug influences the susceptibility of the brain to cortical spreading depression with acute administration. The combined data show the relationship of migraine aura to cortical spreading depression may have some nuances yet to be identified.

Positive botulinum toxin type a response is a prognosticator for migraine surgery success

BACKGROUND

The objective of the study was to determine whether botulinum toxin type A injections can serve as a prognosticator for migraine surgery success.

METHODS

Patients who underwent migraine surgery from 2000 to 2010 by the senior author (B.G.) were reviewed. Patients were included if they had botulinum toxin type A injection before surgery; had completed postinjection, postsurgery Migraine Headache Questionnaires; and had at least 1-year follow-up. Outcome variables include patient demographics and Migraine Headache Index. Treatment success was defined as at least a 50 percent reduction in Migraine Headache Index.

RESULTS

One hundred eighty-eight patients were included; 144 reported successful migraine headache reduction after injection (success group) and 44 did not (failure group). The groups were well matched for age, migraine headache characteristics, and number of surgical sites (p > 0.05). The surgery success rate was significantly higher in the success group overall (90.3 percent versus 72.3, p = 0.003), and in patients who reported botulinum toxin type A success and subsequent same-site surgery (97.9 percent versus 71.4 percent, p < 0.0001). Botulinum toxin type A success was prognostic for surgery success at the frontal trigger site (trigger site I) (92.5 percent versus 69.2 percent, p = 0.012), the temporal trigger site (trigger site II) (95.5 percent versus 73.3 percent, p = 0.005), and the occipital trigger site (trigger site IV) (95.9 percent versus 62.5 percent, p = 0.0003). Six patients had exclusively septum or turbinate (site III) surgery, and all failed injections.

CONCLUSIONS

Positive botulinum toxin type A response is a significant predictor of migraine surgery success. When injections fail, nonmuscular abnormalities should be considered.

Headache and facial pain: differential diagnosis and treatment

Headaches affect 90% of the population sometime during their life. Most are benign and fleeting, some are serious and life-threatening, and others require ongoing medical consultation and treatment. A careful history and physical is necessary to establish a differential diagnosis and to guide the choice of testing to make an accurate diagnosis. The most common types of headaches are discussed in this review. They are divided into primary and secondary headache disorders as classified by the International Headache Society. Primary headache disorders include migraine without and with aura, cluster and tension-type headaches. Secondary headaches are those that occur as a result of some other disorder and include brain tumors, rhinosinusitis, diseases of intracranial and extracranial vasculature, and temporomandibular joint disease.

Long-term improvement in refractory headache following ozone therapy

BACKGROUND

Headache afflicts approximately 10%-15% of the general population. Mixed results are obtained from various therapies, usually drugs, but also oxygen inhalation, behavioral psychology, physical therapy, and peripheral or central neurostimulation. When refractory to treatment, it has severe impact on quality of life. OBJECTIVES/SUBJECTS: Five (5) patients are presented who had suffered from severe/persistent headache refractory to standard management (including 5-HT1 agonist triptan drugs) and were treated with ozone therapy.

INTERVENTIONS

Ozone administration was by major autohemotherapy. The procedure involved venous blood drawn into a sterile single-use glass bottle containing anticoagulant, gently mixed with an equal volume of O3/O2 gas mixture (prefiltered through a sterile 0.20-μm filter) and slowly reinfused back into the donor patient via the antecubital vein.

OUTCOME MEASURES

The analyzed parameters were analgesia requirements, days of sick leave due to headache, number of headache events, and pain intensity according to the visual analogue scale (VAS); these recorded at three time points: pre-ozone therapy, post-ozone therapy, and before the last follow-up (mean: 64.6±36.8 months).

RESULTS

The number of headache episodes pretreatment (n=80; range 5-200) was significantly decreased during the first 6 months post-treatment (n=0, range 0-1; p=0.042) and over the 6 months before the last follow-up visit (n=1, range 0-2; p=0.043). The corresponding VAS scores were 8.7±0.8 pretreatment versus 1.1±2.5 the 6 months post-treatment (p=0.003) and versus 3.1±3.3 the 6 months before last follow-up visit (p=0.036).

CONCLUSIONS

Ozone therapy decreased headache episodes and pain severity over a protracted period. This novel approach is effective and merits further research.

Lack of migraine in headaches of familial dysautonomia patients

Familial Dysautonomia (FD) is an autosomal recessive genetic disease where autonomic and sensory functions are defective affecting many body systems including the vascular. Plasma level of the neurotransmitter Calcitonin Gene Related Peptide (CGRP) is decreased in FD patients. This compound has been implicated to take part in the pathogenesis of migraine. We aimed to evaluate the symptoms of headaches in FD patients and to test the hypothesis that these patients will have a low incidence of migrainous headache. Sixty-five FD patients were evaluated by a medical headache questionnaire. Mean age was 23.73 + 10.82 years (mean 21 years) and there were 37 males (57 %).Thirty-eight patients (58.5 %) described having episodic headache conforming to criteria of tension headache, and in 17 of those 38 (44.7 %) headache were dependent on changes in blood pressure, except from one patient who had complaints that matched diagnosis of acephalic migraine. None of the patients had symptoms compatible with migraine or cluster headache. Results show that the headache is a very common complaint in FD, there is lack of migraine symptoms in this group. This might be attributed to defective sensory innervation and deficiency of CGRP. FD could be regarded as a human model for CGRP deficiency when studying the pathogenesis of migraine.

Sumatriptan inhibition of N-type calcium channel mediated signaling in dural CGRP terminal fibres

The selective 5-HT₁ receptor agonist sumatriptan is an effective therapeutic for migraine pain yet the antimigraine mechanisms of action remain controversial. Pain-responsive fibres containing calcitonin gene-related peptide (CGRP) densely innervating the cranial dura mater are widely believed to be an essential anatomical substrate for the development of migraine pain. 5-HT₁ receptors in the dura colocalize with CGRP fibres in high density and thus provide a possible peripheral site of action for sumatriptan. In the present study, we used high-resolution optical imaging selectively within individual mouse dural CGRP nociceptive fibre terminations and found that application of sumatriptan caused a rapid, reversible dose-dependent inhibition in the amplitude of single action potential evoked Ca²⁺ transients. Pre-application of the 5-HT₁ antagonist GR 127935 or the selective 5-HT(1D) antagonist BRL 15572 prevented inhibition while the selective 5-HT(1B) antagonist SB 224289 did not, suggesting this effect was mediated selectively through the 5-HT(1D) receptor subtype. Sumatriptan inhibition of the action potential evoked Ca²⁺ signaling was mediated selectively through N-type Ca²⁺ channels. Although the T-type Ca²⁺ channel accounted for a greater proportion of the Ca²⁺ signal it did not mediate any of the sumatriptan inhibition. Our findings support a peripheral site of action for sumatriptan in inhibiting the activity of dural pain fibres selectively through a single Ca²⁺ channel subtype. This finding adds to our understanding of the mechanisms that underlie the clinical effectiveness of 5-HT₁ receptor agonists such as sumatriptan and may provide insight for the development of novel peripherally targeted therapeutics for mitigating the pain of migraine.

Beyond neurovascular: migraine as a dysfunctional neurolimbic pain network

No single model of migraine explains all of the known features of the disorder. Migraine has recently been characterized as an abnormality in pain-modulating circuits in the brainstem. The periaqueductal gray appears to have a critical role in migraine genesis and has been labeled the "migraine generator." The concept of a "pain matrix," rather than a specific locus of pain, is widely accepted in the pain literature and offers a new dimension to understanding migraine. Recent neuroimaging studies of migraineurs suggest altered functional connectivity between brainstem pain-modulating circuits and cortical (limbic) centers. Numerous clinical observations suggest that limbic influences play an important role in migraine expression. We propose a model of migraine as a dysfunction of a "neurolimbic" pain network. The influence between brainstem and cortical centers is bidirectional, reflecting the bidirectional interaction of pain and mood. Neurolimbic dysfunction may increase as migraine becomes more chronic or refractory. The neurolimbic model expands the model of migraine as a dysfunction of brainstem nuclei. A neurolimbic model may help bridge a gap in understanding the migraine attack, the interictal dysfunctions of episodic migraine, the progression to chronic migraine, and the common comorbidities with other disorders (such as fibromyalgia, irritable bowel syndrome, and mood and anxiety disorders), which may also be considered neurolimbic. A neurolimbic model of migraine may be a useful heuristic that would impact both clinical treatment and research agendas, as well as education of physicians and patients.