Telmisartan in Migraine Prophylaxis: A Randomized, Placebo-Controlled Trial

Arterial hypertension in the chronic evolution of migraine: bystander or risk factor? An overview

BACKGROUND

Several risk factors are associated with the chronic evolution of migraine. Clinical and preclinical studies have provided data about the role of hypertension (HT) as one of the potential modifiable risk factors of chronic migraine (CM). This review is focused on the biological and clinical evidence supporting common mechanisms underlying HT and migraine and the potential role of HT in the transition from episodic to chronic migraine.

METHODS

We conducted a narrative review from a literature search covering the available evidence from studies investigating: i) the role of HT in the transition to CM in clinical practice; ii) the biological mechanisms potentially underpinning the association between HT and evolution to CM; iii) the role of antihypertensive medications in migraine prophylaxis.

RESULTS

HT proved to be at the base of multiple mechanisms underlying migraine and migraine chronicization. Endothelial dysfunction, blood-brain barrier alterations, calcitonin gene-related peptide signaling, and renin-angiotensin-aldosterone system dysregulation are involved in the worsening effect of HT on migraine frequency, and the role of HT in the transition to CM is supported by clinical observations.

CONCLUSIONS

The observed evidence supports HT contribution to CM evolution due to shared pathophysiologic mechanisms. While a bidirectional influence appears to be ascertained, data are still lacking about the one-way role of HT as direct risk factor for CM transition. Further research is needed to confirm a causal role of HT in this process.

The Renin Angiotensin System as a Therapeutic Target in Traumatic Brain Injury

Traumatic brain injury (TBI) is a major public health problem, with limited pharmacological options available beyond symptomatic relief. The renin angiotensin system (RAS) is primarily known as a systemic endocrine regulatory system, with major roles controlling blood pressure and fluid homeostasis. Drugs that target the RAS are used to treat hypertension, heart failure and kidney disorders. They have now been used chronically by millions of people and have a favorable safety profile. In addition to the systemic RAS, it is now appreciated that many different organ systems, including the brain, have their own local RAS. The major ligand of the classic RAS, Angiotensin II (Ang II) acts predominantly through the Ang II Type 1 receptor (AT1R), leading to vasoconstriction, inflammation, and heightened oxidative stress. These processes can exacerbate brain injuries. Ang II receptor blockers (ARBs) are AT1R antagonists. They have been shown in several preclinical studies to enhance recovery from TBI in rodents through improvements in molecular, cellular and behavioral correlates of injury. ARBs are now under consideration for clinical trials in TBI. Several different RAS peptides that signal through receptors distinct from the AT1R, are also potential therapeutic targets for TBI. The counter regulatory RAS pathway has actions that oppose those stimulated by AT1R signaling. This alternative pathway has many beneficial effects on cells in the central nervous system, bringing about vasodilation, and having anti-inflammatory and anti-oxidative stress actions. Stimulation of this pathway also has potential therapeutic value for the treatment of TBI. This comprehensive review will provide an overview of the various components of the RAS, with a focus on their direct relevance to TBI pathology. It will explore different therapeutic agents that modulate this system and assess their potential efficacy in treating TBI patients.

The effect of blood pressure lowering medications on the prevention of episodic migraine: A systematic review and meta-analysis

BACKGROUND

Currently, only a few specific blood pressure-lowering medications are recommended for migraine prevention. Whether benefits extend to other classes or drugs is uncertain.

METHODS

Embase, MEDLINE, and the Cochrane Central Registry of Controlled Trials were searched for randomized control trials on the effect of blood pressure-lowering medications compared with placebo in participants with episodic migraine. Data were collected on four outcomes - monthly headache or migraine days, and monthly headache or migraine attacks, with a standardised mean difference calculated for overall. Random effect meta-analysis was performed.

RESULTS

In total, 50 trials (70% of which were crossover) were included, comprising 60 comparisons. Overall mean age was 39 years, and 79% were female. Monthly headache days were fewer in all classes compared to placebo, and this was statistically significant for all but one class: alpha-blockers -0.7 (95% CI: -1.2, -0.1), angiotensin-converting enzyme inhibitors -1.3 (95% CI: -2.9, 0.2), angiotensin II receptor blockers -0.9 (-1.6, -0.1), beta-blocker -0.4 (-0.8, -0.0) and calcium channel blockers -1.8 (-3.4, -0.2). Standardised mean difference was significantly reduced for all drug classes and was separately significant for numerous specific drugs: clonidine, candesartan, atenolol, bisoprolol, metoprolol, propranolol, timolol, nicardipine and verapamil.

CONCLUSION

Among people with episodic migraine, a broader number of blood pressure-lowering medication classes and drugs reduce headache frequency than those currently included in treatment guidelines.Trial Registration: The study was registered at PROSPERO (CRD42017079176).

The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regression

BACKGROUND

Migraine affects 1.1 billion people globally and is the second leading cause of disability worldwide. In clinical trials, treatment efficacy is evaluated by comparing the differential responses in the treatment and placebo arms. Although placebo response in preventive migraine trials has been studied, there is limited research examining temporal trends. This study evaluates the trend of placebo response over thirty years in migraine prevention trials and investigates the association of potential confounders, such as patient, treatment, and study characteristics on placebo response using meta-analysis with regression.

METHODS

We conducted literature searches from January 1990 to August 2021 in bibliographical databases (PubMed, Cochrane Library, and EMBASE). Studies were selected according to PICOS criteria and included randomized, double-blind, placebo-controlled trials evaluating preventive migraine treatments in adult patients diagnosed with episodic or chronic migraine, with or without aura. The protocol was registered with PROSPERO (CRD42021271732). Migraine efficacy outcomes included were either continuous (e.g., monthly migraine days) or dichotomous (e.g., ≥ 50% responder rate (yes/no)). We assessed the correlation of the change in outcome from baseline in the placebo arm, with the year of publication. The relationship between placebo response and year of publication was also assessed after accounting to confounders.

RESULTS

A total of 907 studies were identified, and 83 were found eligible. For the continuous outcomes, the change from baseline in mean placebo response showed an increase over the years (rho = 0.32, p = 0.006). The multivariable regression analysis also showed an overall increase in placebo response over the years. The correlation analysis of dichotomous responses showed no significant linear trend between publication year and mean placebo response (rho = 0.08, p = 0.596). Placebo response also varied by route of administration.

CONCLUSION

Placebo response increased over the past 30 years in migraine preventive trials. This phenomenon should be considered when designing clinical trials and conducting meta-analyses.

Association between migraine or severe headache and hypertension among US adults: A cross-sectional study

BACKGROUND AND AIMS

Epidemiological evidence of the association between migraines, severe headaches, and hypertension is contradictory. Hypertension is a critical risk factor for cardiovascular diseases. Migraine is a common neurological disease and a major cause of disability worldwide. Therefore, we aimed to investigate the relationship between migraine, severe headaches, and hypertension among US adults.

METHODS AND RESULTS

Cross-sectional data from 5716 subjects were obtained from the National Health and Nutrition Examination Survey between 1999 and 2004. Weighted logistic regression models investigated the association between migraines, severe headaches, and hypertension. In total, 5716 subjects were enrolled in the present study, of whom 1134 (19.8%) had migraine or severe headaches. Participants with migraine were predominantly younger females and had a higher body mass index (BMI), lower educational level, lower dietary intake of potassium and calcium, lower serum levels of total cholesterol (TC), creatinine, and hemoglobin, as well as a higher estimated glomerular filtration rate (eGFR) (all P < 0.05). After fully adjusting for potential confounders, migraine or severe headaches were positively associated with hypertension (OR 1.25, 95% CI: 1.03-1.53).

CONCLUSION

Our study found a positive association between migraine, severe headaches, and hypertension. Further studies are needed to verify the causality of this association and elucidate the underlying mechanisms.

Consensus of the Brazilian Headache Society (SBCe) for prophylactic treatment of episodic migraine: part II

BACKGROUND

Migraine affects 1 billion people worldwide and > 30 million Brazilians; besides, it is an underdiagnosed and undertreated disorder.

OBJECTIVE

The need to disseminate knowledge about the prophylactic treatment of migraine is known, so the Brazilian Headache Society (SBCe, in the Portuguese acronym) appointed a committee of authors with the objective of establishing a consensus with recommendations on the prophylactic treatment of episodic migraine based on articles from the world literature as well as from personal experience.

METHODS

Meetings were held entirely online, with the participation of 12 groups that reviewed and wrote about the pharmacological categories of drugs and, at the end, met to read and finish the document. The drug classes studied in part II of this Consensus were: antihypertensives, selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, calcium channel blockers, other drugs, and rational polytherapy.

RESULTS

From this list of drugs, only candesartan has been established as effective in controlling episodic migraine. Flunarizine, venlafaxine, duloxetine, and pizotifen were defined as likely to be effective, while lisinopril, enalapril, escitalopram, fluvoxamine, quetiapine, atorvastatin, simvastatin, cyproheptadine, and melatonin were possibly effective in prophylaxis of the disease.

CONCLUSIONS

Despite an effort by the scientific community to find really effective drugs in the treatment of migraine, given the large number of drugs tested for this purpose, we still have few therapeutic options.

The Primary Care Management of Headache: Synopsis of the 2020 U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guideline

INTRODUCTION

In June of 2020, the U.S. DVA and DoD approved a new joint clinical practice guideline for assessing and managing patients with headache. This guideline provides a framework to evaluate, treat, and longitudinally manage the individual needs and preferences of patients with headache.

METHODS

In October of 2018, the DVA/DoD Evidence-Based Practice Work Group convened a guideline development panel that included clinical stakeholders and conformed to the National Academy of Medicine's tenets for trustworthy clinical practice guidelines.

RESULTS

The guideline panel developed key questions, systematically searched and evaluated the literature, created a 1-page algorithm, and advanced 42 recommendations using the Grading of Recommendations Assessment, Development, and Evaluation system.

CONCLUSION

This synopsis summarizes the key features of the guideline in three areas: prevention, assessing and treating medication overuse headache, and nonpharmacologic and pharmacologic management of headache.

Revised guidelines of the French headache society for the diagnosis and management of migraine in adults. Part 2: Pharmacological treatment

The French Headache Society proposes updated French guidelines for the management of migraine. This article presents the second part of the guidelines, which is focused on the pharmacological treatment of migraine, including both the acute treatment of attacks and the prophylaxis of episodic migraine as well as chronic migraine with and without medication overuse. The specific situations that can be encountered in women with migraine are also discussed, including pregnancy, menstrual migraine, contraception and hormonal replacement therapy.

Hypertension and Migraine: Time to Revisit the Evidence

PURPOSE OF REVIEW

It was reported that migraine was associated with increased vascular risks, and the association between high blood pressure (BP) and migraine was believed by some to be the missing link. The current review focused on the associations between migraine and hypertension and BP per se, and evidence on the directionality of the associations was also reviewed.

RECENT FINDINGS

In cross-sectional studies, the findings regarding whether migraine was associated with hypertension were inconsistent, and positive, neutral, or even inverse associations were reported. When individual BP parameters were examined separately, migraine was associated with higher diastolic BPs, and perhaps lower pulse pressures, although the associations with systolic BPs were incongruent. When studies mainly recruiting elderly patients are excluded, it appeared that studies reporting a positive association between migraine and high BPs, particularly high diastolic BPs, outnumbered those with an inverse or neutral association. In longitudinal studies, there was evidence that migraine patients were at increased risks of developing hypertension at follow-up. However, studies examining whether high BP could predict new-onset migraine yielded conflicting results. The association between migraine and hypertension is still a controversial issue, and a firm conclusion is precluded by the heterogeneities in methodologies and study populations. Migraine patients are at increased risk of developing hypertension. However, whether hypertension predicts migraine remains inconclusive. Further studies are needed to clarify the complicated association between BP and migraine.

Real world effectiveness and tolerability of candesartan in the treatment of migraine: a retrospective cohort study

To date, two randomized, controlled studies support the use of candesartan for migraine prophylaxis but with limited external validity. We aim to evaluate the effectiveness and tolerability of candesartan in clinical practice and to explore predictors of patient response. Retrospective cohort study including all patients with migraine who received candesartan between April 2008-February 2019. The primary endpoint was the number of monthly headache days during weeks 8-12 of treatment compared to baseline. Additionally, we evaluated the frequency during weeks 20-24. We analysed the percentage of patients with 50% and 75% response rates and the retention rates after three and 6 months of treatment. 120/4121 patients were eligible, aged 45.9 [11.5]; 100 (83.3%) female. Eighty-four patients (70%) had chronic migraine and 53 (42.7%) had medication-overuse headache. The median number of prior prophylactics was 3 (Inter-quartile range 2-5). At baseline, patients had 20.5 ± 8.5 headache days per month, decreasing 4.3 ± 8.4 days by 3 months (weeks 12-16) and by 4.7 ± 8.7 days by 6 months (paired Student's t-test, p < 0.001). The percentage of patients with a 50% response was 32.5% at 3 months and 31.7% at 6 months, while the retention rate was 85.0% and 58.3%. The number of prior treatments (Odds ratio 0.79, 95% CI 0.64-0.97) and the presence of daily headache (Odds ratio 0.39, 95% CI 0.16-0.97) were associated with a lower probability of response. Candesartan showed beneficial effects in the preventive treatment of migraine in clinical practice, including patients with chronic migraine, medication-overuse headache and resistance to prior prophylactics.

Angiotensin II and Angiotensin Receptors 1 and 2-Multifunctional System in Cells Biology, What Do We Know?

For years, the renin-angiotensin system (RAS) has been perceived as a system whose role is to primarily modulate the functioning of the cardiovascular system. Years of research into the role of RAS have provided the necessary data to confirm that the role of RAS is very complex and not limited to the cardiovascular system. The presence of individual elements of the renin-angiotensin (RA) system allows to control many processes, ranging from the memorization to pro-cancer processes. Maintaining the proportions between the individual axes of the RA system allows for achieving a balance, often called homeostasis. Thus, any disturbance in the expression or activity of individual RAS elements leads to pathophysiological processes.

Renin-Angiotensin-Aldosterone System and Migraine: A Systematic Review of Human Studies

Migraine is a common neurologic condition marked by recurrent episodes of headache. Its pathophysiology is highly complex involving neuronal, inflammatory and vascular mechanisms. The Renin-Angiotensin System (RAS) can modulate all these mechanism, being a potential pharmacological target for migraine treatment. We carried out a systematic review of the studies evaluating the involvement of RAS in patients with migraine. There is evidence from genetic studies exploring the relation between migraine and RAS-related genes and from clinical trials evaluating the efficacy of Angiotensin II Type 1 (AT1) receptor antagonists and angiotensin converting enzyme inhibitors in migraine prophylaxis. RAS seems to play a role in the pathophysiology of migraine, but more direct evidence is still missing.

Lack of association between angiotensin-converting enzyme inhibitors and angiotensin receptor blockers and pain improvement in patients with oral cancer

Background

There is a growing body of literature implicating angiotensin II in the modulation of tumour-associated inflammation and pain. However, the impact of angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs) on pain and inflammation has not yet been studied in oral cancers. The objective is to investigate the role of ACEi and ARB pharmacotherapy on preoperative pain and inflammatory biomarkers, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR), in patients with oral cancer.

Methods

We performed a retrospective study on patients who underwent oral cancer surgery. The Wilcoxon rank-sum test or Kruskal-Wallis analysis was used to evaluate differences in demographic, tumour-related and preoperative characteristics and amongst patients using ARBs, ACEis and no treatment. Multivariable analysis was fitted to estimate the effects of important covariates on severe preoperative pain.

Results

A total of 162 patients with oral malignancies were included in the study. After adjusting for significant covariates, patients with perineural invasion were found to have higher levels of pain (p = 0.0278). Similarly, patients taking ARBs were found to have lower levels of perineural invasion (p = 0.035). The analysis did not demonstrate a significant difference in pain levels when comparing ARBs or ACEis to the no treatment group (p = 0.250). Furthermore, the use of ARB or ACEi did not significantly alter preoperative NLR (p = 0.701) or MLR (p = 0.869).

Conclusions

When compared to no treatment, ARBs and ACEis are not associated with significant analgesic effect or decreased inflammatory scores (NLR, PLR and MLR).

The relation between the placebo response, observed treatment effect, and failure to meet primary endpoint: A systematic review of clinical trials of preventative pharmacological migraine treatments

OBJECTIVE

To evaluate the association between the degree of response to placebo in migraine studies and the observed difference between drug and placebo across studies of preventative treatments for migraine.

METHODS

A systematic review was performed using MEDLINE and the Cochrane Central Register of Controlled Clinical Trials from January 1988 to June 2019. Randomized, double-blind, parallel-group, placebo-controlled trials on oral or injection preventative treatments for migraine were included. Single- and multi-variable linear regression analyses were performed on the placebo-subtracted response rate (i.e. placebo responders subtracted from active responders), and the proportion of placebo responders. Fisher's exact tests were performed on the level of placebo response and the success in meeting the study's primary endpoint.

RESULTS

After adjusting for route of administration and number of randomized subjects, there was a statistically significant association between the proportion of patients who were placebo responders and the placebo-subtracted response rate (b = -0.27, p = 0.02). There was a statistically significant difference in trial success rate (60%) between studies with ≤20% placebo responders and studies with > 30% placebo responders (p = 0.03).

CONCLUSION

Considering the detrimental impact that high placebo response can have on clinical trials, it is imperative to find effective solutions to decrease the placebo response and increase assay sensitivity.

Altered Serum Levels of Renin-Angiotensin System Markers in Migraine

OBJECTIVE

To compare the serum levels of renin-angiotensin system (RAS) components between patients with migraine and healthy controls, and to evaluate whether these levels are associated with migraine severity. We hypothesized that migraine would be associated with the activation of the inflammatory arm of the RAS, possibly leading to increased levels of angiotensin (Ang) II.

BACKGROUND

Recent studies have proposed the use of drugs that interfere with RAS, a hormonal system primarily implicated in blood pressure regulation, as a prophylactic strategy for migraine. However, no previous studies have directly assessed RAS components in migraine.

METHODS

This was a cross-sectional study involving 30 patients with episodic migraine who were in the interictal period and 20 healthy controls. This study was conducted at Hospital das Clínicas (Universidade Federal de Minas Gerais, Belo Horizonte, Brazil) outpatient clinic. Headache severity was evaluated using the Headache Impact Test, version 6 (HIT-6) and the Migraine Disability Test (MIDAS) questionnaires. Given that migraine is comorbid with mood disorders, depressive and anxious symptoms were evaluated using the Beck Anxiety and Depression Inventories (BDI and BAI), respectively. Clinical and demographic data were also collected. Serum levels of angiotensin-converting enzyme (ACE), ACE2, Ang II, and Ang (1-7) were measured by enzyme-linked immunosorbent assay.

RESULTS

Patients with migraine and controls were comparable in age, body mass index, blood pressure, and depressive and anxious symptoms. Patients with migraine showed lower levels of ACE [85.2 (66.8, 101.2) vs 65.5 (54.2, 77.5); P = .005] and lower ACE/ACE2 ratio [4.3 (3.4, 5.2) vs 3.5 (2.9, 4.1); P = .032] than controls. Conversely, patients with migraine had higher levels of Ang II [309.7 ± 147.4 vs 605.4 ± 200.4; difference: -287.1 (95% CI: -391.4--182.8), P < .001] and Ang (1-7) [214.4 ± 155.8 vs 397.9 ± 217.9; difference: -184.6 (95% CI: -296.7--72.6), P = .001] than controls. There were no correlations between RAS serum markers and migraine severity scores (HIT and MIDAS) or depressive and anxious symptoms (BDI and BAI) (P > .05).

CONCLUSIONS

Altogether, our results suggest the participation of RAS in migraine pathophysiology, but not in its severity.

The Risks or Lack Thereof of Migraine Treatments in Vascular Disease

PREMISES

Patients with migraine have a co-morbidity with vascular diseases such as hypertension, coronary heart disease, and stroke.

PROBLEM

This overview gives recommendations for the therapy of acute migraine attacks and for migraine  prevention in patients with vascular diseases. In particular, the use of triptans in patients with vascular diseases is discussed.

POTENTIAL SOLUTIONS

Currently, there is a contraindication for the use of the triptans in patients with vascular disease, although there is no evidence that triptans increase the risk of heart attacks or stroke.

Hypertension and Headache: the Effect of Antihypertensive Drugs

Headache is considered to be one of the main symptoms of arterial hypertension (HT). Complaints of headache are presented by many patients with HT: from 44% to 87%. It is obvious that the majority of complaints of headache in patients with HT is not due to headaches due to increased blood pressure (BP), but multimorbidity (polymorbidity) – the presence of coexisting primary headaches, most often, as in the population as a whole, chronic tension headache (57-85%) and migraine (15-30%). On the other hand, the frequency of HT in patients with migraine ranges from 32% to 44%. The relationship between migraine and HT may be due to common exogenous (external) and endogenous (genetic) factors, as well as common pathophysiological mechanisms. External risk factors, which can be associated with both migraine and HT, include the nature of the diet (excessive consumption of table salt with food), low physical activity, chronic stress; both diseases are also associated with the presence of a connection with the metabolic syndrome. The role of hyperactivation of the renin-angiotensin-aldosterone and adrenergic system and endothelial dysfunction are actively discussed. Angiotensin-converting enzyme takes an active part in the BP control and vascular tone; it is known that some angiotensin converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) have demonstrated efficacy in preventing migraine attacks. The presence of HT can contribute to the chronic course of primary headache, and effective treatment of HT with antihypertensive drugs, on the contrary, can have a positive effect on the course of primary headaches. Antihypertensive drugs reduce the frequency of headaches compared to placebo, but heterogeneity between different classes was revealed. There was a statistically significant decrease in the frequency of headaches compared to placebo during treatment with beta-blockers, ACEI, ARB, diuretics, while calcium antagonists did not reduce the frequency of headaches. According to a number of studies, the frequency of headaches during the treatment with ARB (candesartan) is comparable to that in the placebo group. Some antihypertensive drugs are used to prevent migraine attacks.

Once-monthly galcanezumab for the prevention of migraine in adults: an evidence-based descriptive review and potential place in therapy

In the last 15 years relevant efforts have been made to demonstrate that calcitonin gene-related peptide (CGRP) antagonism is a valuable and druggable mechanism for treatment or prevention of migraine. Galcanezumab is one of the antibodies developed and studied to prevent migraine by targeting CGRP. The scope of this review is to report data currently available on galcanezumab. According to available data, galcanezumab is safe and efficacious in preventing migraine in episodic migraine patients, also reducing disability and functional impairment due to the disorder. In September 2018, galcanezumab was approved in the USA for the prevention of migraine in adults. The placement of galcanezumab into the current therapeutic scenario will be a revolution for migraine patients, and probably in a less near future also for patients affected by other primary headaches.

Other Preventive Anti-Migraine Treatments: ACE Inhibitors, ARBs, Calcium Channel Blockers, Serotonin Antagonists, and NMDA Receptor Antagonists

PURPOSE OF REVIEW

Migraine causes more years of life lived with disability than almost any other condition in the world and can significantly impact the lives of individuals with migraine, their families, and society. The use of medication for the prevention of migraine is an integral component to reducing disability caused by migraine. There are many different drug classes that have been investigated and shown efficacy in migraine prophylaxis. This article examines several of the classes of medications that are used for migraine preventive treatment, specifically, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, serotonin antagonists, alpha-adrenergic agonists, and N-methyl-D-aspartic acid receptor antagonists.

RECENT FINDINGS

There have been randomized control trials investigating medications in these drug classes since the most recent guidelines for migraine prevention in adults were published by the American Academy of Neurology, American Headache Society, and the Canadian Headache Society. In these investigations, enalapril, candesartan, and memantine all demonstrated efficacy for migraine prevention. The evidence for these and the aforementioned drug classes are reviewed. When oral medications are being selected for migraine prevention, comorbid and coexistent medical conditions, concomitant medications, patient preference, and pregnancy and breast-feeding plans should be considered. Within the drug classes discussed, memantine and candesartan have a moderate level of evidence for efficacy.

Treatment of migraine attacks and prevention of migraine: Guidelines by the German Migraine and Headache Society and the German Society of Neurology

In collaboration with some of the leading headache centres in Germany, Switzerland and Austria, we have established new guidelines for the treatment of migraine attacks and the prevention of migraine. A thorough literature research of the last 10 years has been the basis of the current recommendations. At the beginning, we present therapeutic novelties, followed by a summary of all recommendations. After an introduction, we cover topics like drug therapy and practical experience, non-effective medication, migraine prevention, interventional methods, non-medicational and psychological methods for prevention and therapies without proof of efficacy.

Pathophysiology of Migraine: A Disorder of Sensory Processing

Plaguing humans for more than two millennia, manifest on every continent studied, and with more than one billion patients having an attack in any year, migraine stands as the sixth most common cause of disability on the planet. The pathophysiology of migraine has emerged from a historical consideration of the "humors" through mid-20th century distraction of the now defunct Vascular Theory to a clear place as a neurological disorder. It could be said there are three questions: why, how, and when? Why: migraine is largely accepted to be an inherited tendency for the brain to lose control of its inputs. How: the now classical trigeminal durovascular afferent pathway has been explored in laboratory and clinic; interrogated with immunohistochemistry to functional brain imaging to offer a roadmap of the attack. When: migraine attacks emerge due to a disorder of brain sensory processing that itself likely cycles, influenced by genetics and the environment. In the first, premonitory, phase that precedes headache, brain stem and diencephalic systems modulating afferent signals, light-photophobia or sound-phonophobia, begin to dysfunction and eventually to evolve to the pain phase and with time the resolution or postdromal phase. Understanding the biology of migraine through careful bench-based research has led to major classes of therapeutics being identified: triptans, serotonin 5-HT1B/1D receptor agonists; gepants, calcitonin gene-related peptide (CGRP) receptor antagonists; ditans, 5-HT1F receptor agonists, CGRP mechanisms monoclonal antibodies; and glurants, mGlu5 modulators; with the promise of more to come. Investment in understanding migraine has been very successful and leaves us at a new dawn, able to transform its impact on a global scale, as well as understand fundamental aspects of human biology.

Preventive Migraine Treatment

PURPOSE OF REVIEW

This article reviews the evidence base for the preventive treatment of migraine.

RECENT FINDINGS

Evidence-based guidelines for the preventive treatment of migraine have recently been published by the American Academy of Neurology (AAN) and the Canadian Headache Society (CHS), providing valuable guidance for clinicians. Strong evidence exists to support the use of metoprolol, timolol, propranolol, divalproex sodium, sodium valproate, and topiramate for migraine prevention, according to the AAN. Based on best available evidence, adverse event profile, and expert consensus, topiramate, propranolol, nadolol, metoprolol, amitriptyline, gabapentin, candesartan, Petasites (butterbur), riboflavin, coenzyme Q10, and magnesium citrate received a strong recommendation for use from the CHS.

SUMMARY

Migraine preventive drug treatments are underutilized in clinical practice. Principles of preventive treatment are important to improve compliance, minimize side effects, and improve patient outcomes. Choice of preventive treatment of migraine should be based on the presence of comorbid and coexistent illness, patient preference, reproductive potential and planning, and best available evidence.

A Comparative Effectiveness Meta-Analysis of Drugs for the Prophylaxis of Migraine Headache

Objective

To compare the effectiveness and side effects of migraine prophylactic medications.

Design

We performed a network meta-analysis. Data were extracted independently in duplicate and quality was assessed using both the JADAD and Cochrane Risk of Bias instruments. Data were pooled and network meta-analysis performed using random effects models.

Data Sources

PUBMED, EMBASE, Cochrane Trial Registry, bibliography of retrieved articles through 18 May 2014.

Eligibility Criteria for Selecting Studies

We included randomized controlled trials of adults with migraine headaches of at least 4 weeks in duration.

Results

Placebo controlled trials included alpha blockers (n = 9), angiotensin converting enzyme inhibitors (n = 3), angiotensin receptor blockers (n = 3), anticonvulsants (n = 32), beta-blockers (n = 39), calcium channel blockers (n = 12), flunarizine (n = 7), serotonin reuptake inhibitors (n = 6), serotonin norepinephrine reuptake inhibitors (n = 1) serotonin agonists (n = 9) and tricyclic antidepressants (n = 11). In addition there were 53 trials comparing different drugs. Drugs with at least 3 trials that were more effective than placebo for episodic migraines included amitriptyline (SMD: -1.2, 95% CI: -1.7 to -0.82), -flunarizine (-1.1 headaches/month (ha/month), 95% CI: -1.6 to -0.67), fluoxetine (SMD: -0.57, 95% CI: -0.97 to -0.17), metoprolol (-0.94 ha/month, 95% CI: -1.4 to -0.46), pizotifen (-0.43 ha/month, 95% CI: -0.6 to -0.21), propranolol (-1.3 ha/month, 95% CI: -2.0 to -0.62), topiramate (-1.1 ha/month, 95% CI: -1.9 to -0.73) and valproate (-1.5 ha/month, 95% CI: -2.1 to -0.8). Several effective drugs with less than 3 trials included: 3 ace inhibitors (enalapril, lisinopril, captopril), two angiotensin receptor blockers (candesartan, telmisartan), two anticonvulsants (lamotrigine, levetiracetam), and several beta-blockers (atenolol, bisoprolol, timolol). Network meta-analysis found amitriptyline to be better than several other medications including candesartan, fluoxetine, propranolol, topiramate and valproate and no different than atenolol, flunarizine, clomipramine or metoprolol.

Conclusion

Several drugs good evidence supporting efficacy. There is weak evidence supporting amitriptyline’s superiority over some drugs. Selection of prophylactic medication should be tailored according to patient preferences, characteristics and side effect profiles.

Migraine and the risk for stroke and cardiovascular disease

Numerous data have pointed to an association between migraine and cardiovascular diseases. The majority of the available data have indicated that migraine with aura can be considered a risk factor for ischemic stroke, whereas migraine without aura cannot be reliably considered as such. High frequency of attacks and a recent onset of migraine have been related to an increased ischemic stroke risk. In addition, in young subjects with ischemic stroke migraine with aura represents an independent risk factor of overall recurrent vascular events and of recurrent ischemic stroke. Also the risk of transient ischemic attack seems to be increased in migraineurs, although this issue has not been extensively investigated. Several studies have also addressed the possible association between migraine and hemorrhagic stroke. Although the results of these individual studies were conflicting, their meta-analysis showed that migraine is associated with a 1.5-fold increase in the risk of hemorrhagic stroke (including intracerebral and subarachnoid hemorrhage). Some studies have identified migraine also as a possible risk factor for cardiac vascular events while others have yielded negative results. A meta-analysis did not show an increased risk of myocardial infarction in subjects with any migraine vs no migraine but subsequently, data has pointed to an association between any migraine with cardiac ischemic disease. Migraine has also been associated by some studies with vascular mortality and with vascular diseases in regions other than the brain and the heart. Several studies have also indicated that compared with nonmigraineurs, migraineurs have a higher burden of asymptomatic white matter brain lesions and, according to some studies, also infarct-like lesions at brain magnetic resonance. The mechanisms underlying the relationship between migraine and cardiovascular disease are still unclear. The possible explanation may rely on a peculiar vascular vulnerability of migraineurs that may contribute to the pathogenesis of migraine and, in the presence of some other unknown factors may also contribute, over time, to the development of cardiovascular disease. At the moment, there are no reliable features that may indicate which subjects, across the overall migraine population, will develop vascular events and so far, no drugs are recommended for the vascular prevention in migraineurs unless other clear indications are present. In general, the acute treatment and the secondary prevention measures of a patient with stroke who has a history of migraine do not differ from that of other stroke patients. There is currently no direct evidence to support that a migraine prophylactic treatment will reduce future stroke risk in secondary prevention.

Association between migraine and ACE gene (insertion/deletion) polymorphism: the BioBIM study

AIM

In the present case-control study, we investigated the correlation between the common ACE insertion/deletion (I/D) polymorphism and migraine.

MATERIALS & METHODS

Genotyping of the ACE I/D variant was performed in 502 Caucasian patients with migraine and 323 age-, sex- and race/ethnicity-matched healthy controls. We investigated associations between ACE genetic variants and sociodemographic and/or clinical features of migraineurs.

RESULTS

We found a significant association between ACE insertion/insertion (I/I) polymorphism and lower use of pharmacological prophylaxis in migraine patients with aura and in those with chronic migraine. Moreover, ACE I/I polymorphism was significantly more common in migraine patients with aura who had a negative family history of migraine.

CONCLUSION

Our data suggest that although the ACE I/D polymorphism is not a direct risk factor for migraine, the ACE I/I genotype may influence the clinical feature of this disease being associated with reduced use of prophylactic agents in patients with migraine with aura and in those with chronic migraine.

Practical implications of the migraine cardio- and cerebrovascular association: unmet needs of patients

BACKGROUND

Numerous studies have described a relationship between migraine and stroke, and there is emerging evidence that migraine is also associated with cardiovascular disease. The combination of migraine and both cerebrovascular and cardiovascular disease has implications for therapy.

METHODS

We conducted a review of the modifications in medical therapy in patients with comorbid migraine and cardio- and cerebrovascular disorders based on publications from the last 15 years.

RESULTS

Some drugs are contraindicated to treat migraine attacks (ergots, triptans) or for migraine prevention in patients after transient ischemic attack (TIA)/ischemic stroke. Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) are contraindicated in patients with cerebral bleeding. Some drugs for the treatment of acute migraine attacks are contraindicated in patients with symptomatic coronary heart disease.

CONCLUSIONS

Given the large number of patients with comorbid migraine and cardiovascular as well as cerebrovascular disease, there is an unmet need to treat these patients.

Role of angiotensin modulation in primary headaches

The renin-angiotensin system (RAS) is a major regulatory system controlling many different homeostatic mechanisms both within the brain and in the periphery. While it is primarily associated with blood pressure and salt/water regulation, increasing evidence points to the involvement of the RAS in both headache disorders specifically and pain regulation in general. Several publications have indicated that drugs blocking various elements of the renin-angiotensin system lead to a reduction in migraine. Additionally, interventions on different angiotensin peptides or their receptors have been shown to both reduce and increase pain in animal models. As such, modulation of the renin-angiotensin system is a promising approach to the treatment of headaches and other pain conditions.

The renin-angiotensin system: a possible contributor to migraine pathogenesis and prophylaxis

The presence of a tissue-based renin-angiotensin system, independent of the systemic one, has been identified in several organs including the brain. Experimental models have suggested the involvement of the renin-angiotensin system in neurogenic inflammation, susceptibility to oxidative stress, endothelial dysfunction, and neuromodulation of nociceptive transmission, thus potentially contributing to the pathogenesis of migraine. Genetic factors that increase susceptibility to migraine may include angiotensin-converting enzyme polymorphism, although available data are controversial. Clinical studies have suggested that angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may be effective in migraine prophylaxis. However, further research should clarify whether the postulated preventive effect is attributable to a pharmacological action over and above the antihypertensive effect and should test their tolerability in subjects with normal blood pressure values. In patients with contraindications or not responding to conventional prophylactic drugs and in patients with comorbid arterial hypertension, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may be used for migraine prophylaxis.

A comparative study of candesartan versus propranolol for migraine prophylaxis: A randomised, triple-blind, placebo-controlled, double cross-over study

Objective

The objective of this article is to see whether the effect of candesartan for migraine prevention, shown in one previous study, could be confirmed in a new study, and if so, whether the effect was comparable to that of propranolol (non-inferiority analysis), and whether adverse events were different.

Methods

In a randomised, triple-blind, double cross-over study, 72 adult patients with episodic or chronic migraine went through three 12-week treatment periods on either candesartan 16 mg, propranolol slow-release 160 mg, or placebo. The main outcome measures were days with migraine headache per four weeks (primary outcome), days with headache, hours with headache, proportion of responders (>50% reduction of migraine days from baseline), and adverse events.

Results

In the modified intention-to treat-analysis, candesartan and propranolol were both superior to placebo: 2.95 (95% confidence interval: 2.35–3.55%) and 2.91 (2.36–3.45%), versus 3.53 (2.98–4.08%) for migraine days per month ( p = 0.02 for both comparisons, Wilcoxon's paired signed rank test, blinded statistical analysis). Candesartan was non-inferior to propranolol (and vice versa). The proportion of responders was significantly higher on candesartan (43%) and propranolol (40%) than on placebo (23%) ( p = 0.025 and <0.050, respectively). There were more adverse events on candesartan ( n = 133%) and propranolol ( n = 143%) than on placebo ( n = 90%), and the adverse event profiles of the active substances differed somewhat.

Conclusion

It is confirmed that candesartan 16 mg is effective for migraine prevention, with an effect size similar to propranolol 160 mg, and with somewhat different adverse events. Trial registration: EUDRACT (2008-002312-7), ClinicalTrials.gov (NCT00884663).

Preventive pharmacologic treatments for episodic migraine in adults

OBJECTIVES

Systematic review of preventive pharmacologic treatments for community-dwelling adults with episodic migraine.

DATA SOURCES

Electronic databases through May 20, 2012.

ELIGIBILITY CRITERIA

English-language randomized controlled trials (RCTs) of preventive drugs compared to placebo or active treatments examining rates of ≥50 % reduction in monthly migraine frequency or improvement in quality of life.

STUDY APPRAISAL AND SYNTHESIS METHODS

We assessed risk of bias and strength of evidence and conducted random effects meta-analyses of absolute risk differences and Bayesian network meta-analysis.

RESULTS

Of 5,244 retrieved references, 215 publications of RCTs provided mostly low-strength evidence because of the risk of bias and imprecision. RCTs examined 59 drugs from 14 drug classes. All approved drugs, including topiramate (9 RCTs), divalproex (3 RCTs), timolol (3 RCTs), and propranolol (4 RCTs); off-label beta blockers metoprolol (4 RCTs), atenolol (1 RCT), nadolol (1 RCT), and acebutolol (1 RCT); angiotensin-converting enzyme inhibitors captopril (1 RCT) and lisinopril (1 RCT); and angiotensin II receptor blocker candesartan (1 RCT), outperformed placebo in reducing monthly migraine frequency by ≥50 % in 200-400 patients per 1,000 treated. Adverse effects leading to treatment discontinuation (68 RCTs) were greater with topiramate, off-label antiepileptics, and antidepressants than with placebo. Limited direct evidence as well as frequentist and exploratory network Bayesian meta-analysis showed no statistically significant differences in benefits between approved drugs. Off-label angiotensin-inhibiting drugs and beta-blockers were most effective and tolerable for episodic migraine prevention.

LIMITATIONS

We did not quantify reporting bias or contact principal investigators regarding unpublished trials.

CONCLUSIONS

Approved drugs prevented episodic migraine frequency by ≥50 % with no statistically significant difference between them. Exploratory network meta-analysis suggested that off-label angiotensin-inhibiting drugs and beta-blockers had favorable benefit-to-harm ratios. Evidence is lacking for long-term effects of drug treatments (i.e., trials of more than 3 months duration), especially for quality of life.

Prophylactic Treatment of Migraine

Migraine is a common chronic neurological disease characterized by episodic attacks of headache and associated symptoms. The pharmacological treatment of migraine may be acute or prophylactic, and patients with frequent, severe headaches often require both approaches. Prophylactic treatment is used to reduce the frequency, duration, or severity of attacks, to enhance the benefits of acute treatments, and to improve patient's ability to function normally. Prophylactic treatment may also prevent progression from episodic migraine to chronic migraine and may result in reductions in health-care cost. The currently available pharmacological options for migraine prophylaxis include a wide array of medications. The major medication groups for prophylactic treatment include β-blockers, anticonvulsant, drugs such as topiramate and valproate, antidepressant drugs, such as amitriptyline and selective serotonin and selective serotonin-norepinephrine reuptake inhibitors (SNRIs), calcium channel antagonists and neurotoxins. The agent for prophylactic treatment should be chosen based on the efficacy and side-effect profile of the drug, and the patient's coexistent and comorbid conditions.

Preventive treatment in migraine and the new US guidelines

Migraine headaches are among the most common headache disorders seen in various practices. The prevalence of migraine headaches is 18% in women and 6% in men. While millions of Americans suffer from migraine headaches, roughly 3%-13% of identified migraine patients are on preventive therapy, while an estimated 38% actually need a preventive agent. The challenge among physicians is not only when to start a daily preventive agent but which preventive agent to choose. Circumstances warranting prevention have been described in the past, and in 2012, a new set of guidelines with an evidence review on preventive medications was published. A second set of guidelines provided evidence on nonsteroidal anti-inflammatory drugs, herbs, minerals, and vitamins for prevention of episodic migraine. This article describes the updated US guidelines for the prevention of migraines and also outlines the major studies from which these guidelines were derived.

Migraine treated using a prophylactic combination of candesartan and hydrochlorothiazide (ECARD Combination Tablets LD)

We describe the use of the antihypertensive, candesartan, with hydrochlorothiazide (ECARD Combination Tablets LD) as a preventive therapy that decreased the frequency of migraine accompanied by premonitory leg edema. Two women (aged 26 and 50 years) presented to hospital with an increasing frequency of migraine without aura accompanied by leg edema. We prescribed ECARD half tablet (candesartan, 2 mg and hydrochlorothiazide, 3.125 mg), and the migraines and leg edema disappeared. The use of ECARD to treat a series of migraines by controlling premonitory leg edema has not been reported. ECARD, combined with a low-dose diuretic, may have been helpful in these patients with the premonitory migraine symptom of leg edema.

Renin angiotensin system: A novel target for migraine prophylaxis

Migraine constitutes 16% of primary headaches affecting 10-20% of general population according to International Headache Society. Till now nonsteroidalanti-inflammatory drugs (NSAIDS), opioids and triptans are the drugs being used for acute attack of migraine. Substances with proven efficacy for prevention include β-blockers, calcium channel blockers, antiepileptic drugs and antidepressants. All the already available drugs have certain limitations. Either they are unable to produce complete relief or 30-40% patients are no responders or drugs produce adverse effects. This necessitates the search for more efficacious and well-tolerated drugs. A new class of drugs like angiotensin-converting enzyme inhibitors (ACE inhibitors) and angiotensin II receptor antagonists have recently been studied for their off label use in prophylaxis of migraine. Studies, done so far, have shown results in favour of their clinical use because of the ability to reduce number of days with headache, number of days with migraine, hours with migraine, headache severity index, level of disability, improved Quality of life and decrease in consumption of specific or nonspecific analgesics. This article reviews the available evidence on the efficacy and safety of these drugs in prophylaxis of migraine and can give physician a direction to use these drugs for chronic migraineurs. Searches of pubmed, Cochrane database, Medscape, Google and clinicaltrial.org were made using terms like ACE inhibitors, angiotensin II receptor antagonists and migraine. Relevant journal articles were chosen to provide necessary information.

Evidence-based guideline update: pharmacologic treatment for episodic migraine prevention in adults: report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Headache Society

OBJECTIVE

To provide updated evidence-based recommendations for the preventive treatment of migraine headache. The clinical question addressed was: What pharmacologic therapies are proven effective for migraine prevention?

METHODS

The authors analyzed published studies from June 1999 to May 2009 using a structured review process to classify the evidence relative to the efficacy of various medications available in the United States for migraine prevention.

RESULTS AND RECOMMENDATIONS

The author panel reviewed 284 abstracts, which ultimately yielded 29 Class I or Class II articles that are reviewed herein. Divalproex sodium, sodium valproate, topiramate, metoprolol, propranolol, and timolol are effective for migraine prevention and should be offered to patients with migraine to reduce migraine attack frequency and severity (Level A). Frovatriptan is effective for prevention of menstrual migraine (Level A). Lamotrigine is ineffective for migraine prevention (Level A).

Migraine and vascular diseases: a review of the evidence and potential implications for management

INTRODUCTION

The higher-than-expected incidence of vascular diseases reported in migraineurs suggests that migraine may, in some cases, be a dangerous condition rather than just a distressing but harmless disorder. We provide a systematic review of data linking migraine to vascular diseases.

MIGRAINE AND VASCULAR DISEASES

Available data indicate an increased risk of ischemic stroke in subjects suffering from migraine with aura. In addition, evidence suggests an association between migraine with aura and cardiac disease, intracerebral hemorrhage, retinal vasculopathy and mortality that needs to be further corroborated; consequently, for those conditions, migraine with aura can be only considered among the less-well-documented risk factors. As the absolute risk of ischemic stroke in the overall migraineur population is low, subjects suffering from migraine with aura should be made aware of the possible link but not unduly alarmed. It is a common notion that the vascular risk of migraineurs may be further increased by the presence of easily treatable vascular risk factors such as arterial hypertension, cigarette smoking and oral contraceptive use.

CONCLUSIONS

Forthcoming guidelines should appropriately recommend supporting migraineurs not only with measures aimed at decreasing headache frequency, thus improving quality of life, but also with general measures and preventive strategies aimed to reduce the overall vascular risk. In fact, headache specialists should take care not only of relieving pain but also of assessing and treating concurrent vascular risk factors, while gynecologists, in particular, should routinely consider the presence and type of migraine before prescribing oral contraceptives.

CONSORT recommendations in abstracts of randomised, controlled trials on migraine and headache

A CONSORT statement on the content of abstracts of randomised, controlled trials (RCTs) was published in 2008. I therefore reviewed the abstracts from 2009 to 2010 published on RCTs in Cephalalgia, Headache and other (non-headache) journals. The following items were reviewed: number of patients, reporting of response either in percentages or absolute values, the use of p values, and effect size with its precision. The latter was recommended in the CONSORT statement. A total of 46 abstracts were reviewed and effect size with 95% confidence intervals was only reported in seven abstracts. The influence of the CONSORT statement on reporting in abstracts has so far only had a limited influence on the headache literature.