Risk factors for migraine disease progression: a narrative review for a patient-centered approach

The headache research priorities: Research goals from the American Headache Society and an international multistakeholder expert group

OBJECTIVE

To identify and disseminate research priorities for the headache field that should be areas of research focus during the next 10 years.

BACKGROUND

Establishing research priorities helps focus and synergize the work of headache investigators, allowing them to reach the most important research goals more efficiently and completely.

METHODS

The Headache Research Priorities organizing and executive committees and working group chairs led a multistakeholder and international group of experts to develop headache research priorities. The research priorities were developed and reviewed by clinicians, scientists, people with headache, representatives from headache organizations, health-care industry representatives, and the public. Priorities were revised and finalized after receiving feedback from members of the research priorities working groups and after a public comment period.

RESULTS

Twenty-five research priorities across eight categories were identified: human models, animal models, pathophysiology, diagnosis and management, treatment, inequities and disparities, research workforce development, and quality of life. The priorities address research models and methods, development and optimization of outcome measures and endpoints, pain and non-pain symptoms of primary and secondary headaches, investigations into mechanisms underlying headache attacks and chronification of headache disorders, treatment optimization, research workforce recruitment, development, expansion, and support, and inequities and disparities in the headache field. The priorities are focused enough that they help to guide headache research and broad enough that they are widely applicable to multiple headache types and various research methods.

CONCLUSIONS

These research priorities serve as guidance for headache investigators when planning their research studies and as benchmarks by which the headache field can measure its progress over time. These priorities will need updating as research goals are met and new priorities arise.

Inflammo-immune perspective on the association of eight migraine risk factors with migraine: a multi-omics Mendelian randomization study

Background

Migraine risk factors are associated with migraine susceptibility, yet their mechanisms are unclear. Evidence suggests a role for inflammatory proteins and immune cells in migraine pathogenesis. This study aimed to examine the inflammo-immune association between eight migraine risk factors and the disorder.

Methods

This study utilized inverse variance weighted (IVW) method and colocalization analysis to explore potential causal relationships between eight migraine risk factors, migraine, 731 immune cells, and 91 circulating inflammatory proteins. Mediation Mendelian randomization (MR) was further used to confirm the mediating role of circulating inflammatory proteins and immune cells between the eight migraine risk factors and migraine.

Results

Migraine risk factors are linked to 276 immune cells and inflammatory proteins, with cigarettes smoked per day strongly co-localized with CD33-HLA DR+ cells. Despite no co-localization, 23 immune cells/inflammatory proteins relate to migraine. Depression, all anxiety disorders, and sleep apnea are correlated with migraine, and all anxiety disorders are supported by strong co-localization evidence. However, the mediating effect of inflammatory proteins and immune cells between eight migraine risk factors and migraine has not been confirmed.

Conclusion

We elucidate the potential causal relationships between eight migraine risk factors, migraine, immune cells, and inflammatory proteins, enhancing our understanding of the molecular etiology of migraine pathogenesis from an inflammatory-immune perspective.

Lack of association between TRPV1 gene polymorphisms and risk of migraine chronification: a case-control study and meta-analysis

OBJECTIVE

To confirm a previously reported association of TRPV1 rs8065080 with the risk of transformation from episodic (EM) to chronic migraine (CM) and to extend knowledge about the role of other TRPV1 single nucleotide polymorphisms (SNPs), we first investigated the impact of three TRPV1 SNPs (rs8065080, rs222747 and rs222749) on the risk of migraine chronification in a case-control study. A systematic review and meta-analysis were then conducted to summarize the accumulated findings.

METHODS

Genotyping of the selected TRPV1 SNPs was performed using TaqMan real-time PCR in 167 EM and 182 CM participants. Crude and adjusted odds ratios with associated 95% confidence intervals were calculated in the log-additive, dominant, and recessive genetic models. A comprehensive literature search was performed in PubMed, Web of Knowledge, Cochrane Library, and OpenGrey until February 2024.

RESULTS

In our case-control study, no association was found between TRPV1 SNPs and the risk of migraine chronification, both in the unadjusted logistic regression models and after adjustment for confounding clinical variables. The results of the meta-analysis with a total of 241 participants with EM and 223 with CM confirmed no association between TRPV1 SNPs and the risk of migraine chronification in any of the genetic models tested.

CONCLUSION

The results of the present case-control study and meta-analysis exclude a major role of TRPV1 rs8065080, rs222747, and rs222749 as risk factors for migraine chronification. However, further research is needed to investigate the gene-gene and gene-environment interactions of TRPV1 SNPs on the risk of transformation from episodic to chronic migraine.

Sex Differences in the Expression of Central Sensitization Symptoms in Migraine: An Observational Study

Background: Migraine is the fourth most common cause of disability in women and the eighth most common cause in men. Central sensitization phenomena predispose to chronic migraine and are generally more pronounced in women. Objective: The aim of this retrospective observational study was to look for sex differences in a population of migraine subjects attending a tertiary headache center, focusing on symptoms of central sensitization such as allodynia and pericranial tenderness. Methods: This study is based on data collected at a tertiary headache center between January 1, 2018, and December 31, 2022. The clinical interview included the main features of migraine, allodynia, a disability questionnaire, the pericranial tenderness score, and anxiety and depression scales. Results: We selected a total of 1,087 migraine subjects (233 men). Osmophobia predominated in women, as did nausea. Disability scores, headache intensity, allodynia, anxiety, and depression predominated in women, without menopausal age playing a role. The frequency of symptomatic medication use was similar in both sexes. Allodynia score was the largest discriminating factor between women and men. Conclusions: Women with migraine are more likely than men to report acute allodynia, nausea, and osmophobia and are also more likely to be anxious, depressed, and disabled. These features appear to be independent of fertile age and are probably related to sex-specific genetic characteristics. These symptoms represent a tendency toward sensory hypersensitivity and central sensitization that should be carefully assessed in both women and men with migraine with a view to possibly predicting chronic development.

Exploring the Causal Relationship Between Migraine and Insomnia Through Bidirectional Two-Sample Mendelian Randomization: A Bidirectional Causal Relationship

Introduction

The intricate relationship between migraine and insomnia has been a subject of great interest due to its complex mechanisms. Despite extensive research, understanding the causal link between these conditions remains a challenge.

Material and Methods

This study employs a bidirectional Mendelian randomization approach to investigate the causal relationship between migraine and insomnia. Risk loci for both conditions were derived from large-scale Genome-Wide Association Studies (GWAS). The primary method of Mendelian Randomization utilized in this study is the Inverse Variance Weighted (IVW) method.

Results

Our findings indicate a bidirectional causal relationship between migraine and insomnia. In the discovery set, migraine had a significant effect on insomnia (OR=1.02, 95% CI=1.02 (1.01-1.03), PIVW=5.30E-04). However, this effect was not confirmed in the validation set (OR=1.03, 95% CI=1.03 (0.87-1.21), PIVW=0.77). Insomnia also had a significant effect on migraine (OR=1.02, 95% CI=1.02 (0.01-1.03), PIVW=2.67E-08), and this effect was validated in the validation set (OR=2.30, 95% CI=2.30 (1.60-3.30), PIVW=5.78E-06).

Conclusion

This study provides meaningful insights into the bidirectional causality between migraine and insomnia, highlighting a complex interplay between these conditions. While our findings advance the understanding of the relationship between migraine and insomnia, they also open up new avenues for further research. The results underscore the need for considering both conditions in clinical and therapeutic strategies.

Therapeutic Patient Education as Part of the Physiotherapy Management of Adults with Headache: A Scoping Review

PURPOSE OF REVIEW

Physiotherapy interventions for headache mostly include exercise and manual therapy. Yet, the complex nature of headache, sometimes characterized by symptoms of facilitated central pain mechanisms, demands an individualized approach in which therapeutic patient education could be supportive. This scoping review aimed to summarize the position of therapeutic patient education within the physiotherapy management of adults with headache. PubMed, EMBASE, Web of Science, and Scopus were searched. The search-query comprised terminology relating to "headache", "education", and "physiotherapy". Eligibility criteria were: adults with headache, interventions including education within the domain of physiotherapy, reviews, clinical trials, cohort, case report, case-control studies.

RECENT FINDINGS

Eleven publications were included from the 281 retrieved publications. These publications were clinical trials (n = 4), reviews (n = 4), case-reports (n = 2), and a guideline (n = 1). Type of headaches studied were migraine (n = 3), post-traumatic headache (n = 2), tension-type headache (n = 2), cervicogenic headache (n = 1), primary headaches (n = 1), chronic daily headache (n = 1), and mixed migraine-cervicogenic headache (n = 1). Education seems an umbrella-term for postural education, lifestyle advice, and pain education. Three themes emerged across the publications: handling headache triggers (migraine, post-traumatic headache), promoting active lifestyle (post-traumatic headache, chronic daily headache, migraine), evaluating posture (post-traumatic headache, chronic daily headache, tension-type headache, cervicogenic headache). All publications recommended education in the management of headache. Only one (of the 11 included) publication described the educational program and determined its efficacy. Based on this scoping review, therapeutic patient education seems supported within physiotherapy management of headache. However, it is unclear how such education is tailored to the specific needs of the individual, the headache subtype, or when it should be added to physiotherapy management of headache.

The role of caffeine in headache disorders

PURPOSE OF REVIEW

Caffeine is known to have both beneficial and adverse effects in individuals with headache disorders. This review describes recent findings regarding caffeine that are relevant to headache disorders and puts these findings into the context of clinical management.

RECENT FINDINGS

Preclinical studies show that caffeine has complex effects on sleep, brain blood flow, and intracranial pressure that may depend on the timing of caffeine intake relative to the sleep-wake cycle. Caffeine metabolism may have significant inter-individual variation that influences its therapeutic and/or adverse effects. Caffeine has acute therapeutic benefit for some primary headache disorders. For migraine, this benefit is predominantly in milder headache without cutaneous allodynia. High levels of caffeine intake may contribute to progression of headache disorders. Caffeine-containing combination analgesics commonly cause medication overuse headache. Abrupt reduction in caffeine consumption is a trigger for migraine that may be important in situations including the hospital setting, religious and cultural fasting, and pregnancy.

SUMMARY

There is not sufficient evidence to support universal guidelines for the use of dietary and medicinal caffeine in headache disorders. A sensible approach based upon available evidence is to limit dietary caffeine intake to moderate amounts with consistent timing before noon, and to use caffeine-containing combination analgesics infrequently for milder headache.

Eating attitudes of migraine patients in Turkey: a prospective multi-center study

BACKGROUND

Migraine is a disease characterized by headache attacks. The disease is multifactorial in etiology and genetic and environmental factors play role in pathogenesis. Migraine can also be accompanied by psychiatric disorders like neurotism and obsessive compulsive disorder. Stress, hormonal changes and certain food intake can trigger attacks in migraine. Previous studies showed that eating attitudes and disorders are prevalant in patients with migraine. Eating disorders are psychiatric disorders related to abnormal eating habits. Both migraine and eating disorders are common in young women and personality profiles of these patient groups are also similar. A possible relationship which shows that migraine and eating habits are related can lead to a better understanding of disease pathogenesis and subsequently new therapeutic options on both entities. Association of migraine in relation to severity, depression and anxiety and eating habits and disorders were aimed to be investigated in this study.

METHODS

The study was designed as a prospective, multi-center, case control study. Twenty-one centers from Turkey was involved in the study. The gathered data was collected and evaluated at a single designated center. From a pool of 1200 migraine patients and 958 healthy control group, two groups as patient group and study group was created with PS matching method in relation to age, body-mass index, marital status and employment status. Eating Attitudes Test-26 (EAT-26), Beck's Depression Inventory (BDI) and Beck's Anxiety Inventory (BAI) were applied to both study groups. The data gathered was compared between two groups.

RESULTS

EAT-26 scores and the requirement for referral to a psychiatrist due to symptoms related to eating disorder were both statistically significantly higher in patient group compared to control group (p = 0.034 and p = 0.0001 respectively). Patients with migraine had higher scores in both BDI and BAI compared to control group (p = 0.0001 and p = 0.0001 respectively). Severity of pain or frequency of attacks were not found to be related to eating attitudes (r:0.09, p = 0.055).

CONCLUSIONS

Migraine patients were found to have higher EAT-26, BDI and BAI scores along with a higher rate of referral to a psychiatrist due to symptoms. Results of the study showed that eating habits are altered in migraine patients with higher risk of eating disorders. Depression and anxiety are also found to be common amongst migraine patients.

Results of a Web-Based Survey on 2565 Greek Migraine Patients in 2023: Demographic Data, Imposed Burden and Satisfaction to Acute and Prophylactic Treatments in the Era of New Treatment Options

Objective: The Greek Society of Migraine and Headache Patients conducted its third in-line population web-based survey in 2023 to ascertain if the burden of the disease and the patients' satisfaction with conventional and novel migraine therapies are changing compared to our previous findings from 2018 and 2020. Methods: The sampling process was based on a random call to participants to reply to a specific migraine-focused self-administered questionnaire, including 83 questions in Greek, which was distributed nationwide through the online research software SurveyMonkey. Results: We eventually enrolled 2565 patients, the majority of which were females. Our findings clearly demonstrate that migraine is still a burdensome condition. The degree of its impact on all aspects of productivity depends on the monthly frequency of migraine and the response rates to acute and prophylactic treatments. A total of 1029 (42.4%) of the patients had visited the emergency room mainly for unresponsiveness to acute treatments or aura-related symptoms. Triptans seem to be partly effective as acute therapies. OnabotulinumtoxinA seems to be effective for almost half of chronic migraine patients (43.9%) to report adequate satisfaction with this treatment (27.8% were "fairly happy", 10.6% were "very happy", and 5.5% were "extremely happy"). Due to their high rates of preventative effectiveness, most respondents treated with anti-CGRP Mabs expressed their optimism concerning their future while living with their migraine (88.25%), as well as towards further improvements in their quality of life (82.8%) status, mostly with fremanezumab. Conclusions: The patients recognize the usefulness of anti-CGRP Mabs in migraine prevention and consequently seem to be more optimistic than before about living with migraine. Considering the market change that is anticipated with the use of gepants and ditans, larger longitudinal population-based studies are warranted to further explore if the new era of migraine therapeutics might further lessen the burden of the disease.

Unsatisfactory response to acute medications does not affect the medication overuse headache development in pediatric chronic migraine

BACKGROUND

Chronic migraine (CM) negatively impacts the quality of life of 2 to 4% of pediatric patients. In adults, CM is frequently linked to medication overuse headache (MOH), but there is a much lower prevalence of MOH in children. A suboptimal response to acute therapies may lead to their reduced use, thus preventing MOH development in children and adolescents. The frequency of patients with CM who do not respond to acute therapies was examined in the present study. We investigated whether the prevalence of MOH was different between responders and non-responders. We also examined whether patients receiving prophylactic therapy had an improved response to acute therapy. Finally, we investigated if there was a difference in the frequency of psychiatric comorbidities between responders and non-responders.

METHODS

We retrospectively analysed clinical data of all chronic pediatric migraineurs under the age of 18 referred to the Headache Centre at Bambino Gesù Children Hospital in June 2021 and February 2023. ICHD3 criteria were used to diagnose CM and MOH. We collected demographic data, including the age at onset of migraine and the age of the CM course. At baseline and after 3 months of preventive treatment, we evaluated the response to acute medications. Neuropsychiatric comorbidities were referred by the children's parents during the first attendance evaluation.

RESULTS

Seventy patients with CM were assessed during the chosen period. Paracetamol was tried by 41 patients (58.5%), NSAIDs by 56 patients (80.0%), and triptans by 1 patient (1.4%). Fifty-one participants (73%) were non-responder to the abortive treatment. The presence of MOH was detected in 27.1% of the whole populations. Regarding our primary aim, MOH was diagnosed in 29% of non-responder patients and 22% of responders (p > 0.05). All patients received preventative treatment. After 3 months of preventive pharmacological therapy, 65.4% of patients who did not respond to acute medications achieved a response, while 34.6% of patients who were non-responder remain non-responder (p < 0.05). Prophylactic therapy was also effective in 69% of patients who responded to acute medication (p < 0.05). Psychiatric comorbidities were detected in 68.6% of patients, with no difference between responders and non-responders (72.2% vs. 67.3%; p = 0.05).

CONCLUSIONS

Despite the high prevalence of unresponsiveness to acute therapies in pediatric CM, it does not act as a protective factor for MOH. Moreover, responsiveness to acute drugs is improved by pharmacological preventive treatment and it is not affected by concomitant psychiatric comorbidities.

Migraine treatment: quo vadis? Real-world data study (2015-2022) in Spain

BACKGROUND

Migraine is a leading cause of disability, estimated to affect one-in-ten people in Spain. This study aimed to describe the management of migraine in Spain and identify improvement areas.

METHODS

Non-interventional, retrospective, cross-sectional cohort study conducted using an electronic medical records database covering visits to public healthcare providers for 3% of the Spanish population. Patients with a migraine diagnosis (ICD-9 346) between 01/2015 and 04/2022 were included, as well as their demographic and clinical characteristics, prescribed migraine treatments and the specialty of the prescribing physicians.

RESULTS

The database included 61,204 patients diagnosed with migraine. A migraine treatment had been prescribed to 50.6% of patients over the last 24 months (only acute to 69.5%, both acute and preventive to 24.2%, and only preventive to 6.3%). The most frequently prescribed treatments were NSAIDs (56.3%), triptans (44.1%) and analgesics (28.9%). Antidepressants were the most common preventive treatment (prescribed to 17.9% of all treated patients and 58.7% of those treated with a preventive medication), and anti-CGRP monoclonal antibodies the least prescribed (1.7%; 5.7%). In 13.4% of cases, preventive medications were the first treatment: alone in 5.8% of cases and together with an acute medication in 7.6%. A fifth of patients who were initially prescribed with only acute treatment were later prescribed a preventive medication (20.7%). On average, it took 29.4 months for this change to occur. Two-thirds of patients started their preventive treatment in primary care (64.2%). The percentage of patients treated by a neurologist increased with the number of received preventive medications. However, 28.8% of patients who had already been prescribed five or more distinct preventive treatments were not treated by a neurologist. Migraine patients had between 1.2- and 2.2-times higher prevalence of comorbidities than the general population, age-gender adjusted.

CONCLUSIONS

Our study emphasizes the need for improved management of migraine in Spain to reduce the risk of chronification and improve patient outcomes. More training and coordination across healthcare professionals is necessary to recognize and address risk factors for migraine progression, including multiple associated comorbidities and several lines of treatment, and to provide personalized treatment plans that address the complex nature of the condition.

Medication "underuse" headache

BACKGROUND

Many risk factors have been associated with migraine progression, including insufficient and ineffective utilization of migraine medications; however, they have been inadequately explored. This has resulted in suboptimal usage of medications without effective altering of prescribing recommendations for patients, posing a risk for migraine chronification.

METHODS

Our aim is to conduct a comprehensive review of the available evidence regarding the underuse of migraine medications, both acute and preventive. The term "underuse" includes, but is not limited to: (1) ineffective use of appropriate and inappropriate medication; (2) underutilization; (3) inappropriate timing of usage; and (4) patient dissatisfaction with medication.

RESULTS

The underuse of both acute and preventive medications has been shown to contribute to the progression of migraine. In terms of acute medication, chronification occurs as a result of insufficient drug use, including failure of the prescriber to select the appropriate type based on pain intensity and disability, patients taking medication too late (more than 60 minutes after the onset or after central sensitization has occurred as evidenced by allodynia), and discontinuation because of lack of effect or intolerable side effects. The underlying cause of inadequate effectiveness of acute medication lies in its inability to halt the propagation of peripheral activation to central sensitization in a timely manner. For oral and injectable preventive migraine medications, insufficient efficacy and intolerable side effects have led to poor adherence and discontinuation with subsequent progression of migraine. The underlying pathophysiology here is rooted in the repetitive stimulation of afferent sensory pain fibers, followed by ascending brainstem pain pathways plus dysfunction of the endogenous descending brainstem pain inhibitory pathway. Although anti-calcitonin gene-related peptide (CGRP) medications partially address pain caused by the above factors, including decreased efficacy and tolerability from conventional therapy, some patients do not respond well to this treatment. Research suggests that initiating preventive anti-CGRP treatment at an early stage (during low frequency episodic migraine attacks) is more beneficial than commencing it during high frequency episodic attacks or when chronic migraine has begun.

CONCLUSIONS

The term "medication underuse" is underrecognized, but it holds significant importance. Optimal usage of acute care and preventive migraine medications could potentially prevent migraine chronification and improve the treatment of migraine attacks.

Acute Treatment of Migraine: Expert Consensus Statements from the United Arab Emirates (UAE)

INTRODUCTION

Migraine, characterized by recurrent headaches and often accompanied by other symptoms like nausea, vomiting, and sensitivity to light and sound, significantly impacts patients' quality of life (QoL) and daily functioning. The global burden of migraines is reflected not only in terms of reduced QoL but also in the form of increased healthcare costs and missed work or school days. While UAE (United Arab Emirates)-specific consensus-based recommendations for the effective use of preventive calcitonin gene-related peptide (CGRP)-based migraine therapies have been published previously, an absence of such regional guidance on the management of acute migraine represents a gap that needs to be urgently addressed.

METHODS

A task force of eight neurologists from the UAE with expertise in migraine management conducted a comprehensive literature search and developed a set of expert statements on the management of acute migraine that were specific to the UAE context. To ensure diverse perspectives are considered, a Delphi panel comprising 16 neurologists plus the task force members was set up. Consensus was achieved using a modified Delphi survey method. Consensus was predefined as a median rating of 7 or higher without discordance (if > 25% of the Delphi panelists rate an expert statement as 3 or lower on the Likert scale). Expert statements achieving consensus were adopted.

RESULTS

The Modified Delphi method was used successfully to achieve consensus on all nine expert statements drafted by the task force. These consensus statements aim to provide a comprehensive guide for UAE healthcare professionals in treating acute migraine. The statements cover all aspects of acute migraine treatment, including what goals to set, the timing of treatment, treatment strategy to use in case of inadequate response to triptans, safety aspects of combining gepants for acute attacks with preventive CGRP-based therapies, special population (pregnant and pediatric patients) considerations, and the management of the most bothersome symptoms (MBS).

CONCLUSIONS

Adopting these consensus statements on the treatment of acute migraine can help enhance patient care, improve outcomes, and standardize treatment practices in the UAE. The collaborative effort of experts with diverse experiences in developing these consensus statements will strengthen the credibility and applicability of these statements to various healthcare settings in the country.

Safety and efficacy of atogepant for the preventive treatment of episodic migraine in adults for whom conventional oral preventive treatments have failed (ELEVATE): a randomised, placebo-controlled, phase 3b trial

BACKGROUND

Atogepant, an oral calcitonin gene-related peptide receptor antagonist, has been approved for the preventive treatment of migraine, but its efficacy and safety in people who have been failed by conventional oral preventive migraine treatments has not yet been evaluated in a dedicated clinical trial. The ELEVATE trial evaluated the safety, tolerability, and efficacy of atogepant for the preventive treatment of episodic migraine in participants for whom two to four classes of conventional oral preventive treatments have failed.

METHODS

ELEVATE was a randomised, double-blind, placebo-controlled, parallel-group, phase 3b trial done at 73 sites in Canada, the Czech Republic, Denmark, France, Germany, Hungary, Italy, the Netherlands, Poland, Russia, Spain, the UK, and the USA. Adults (18-80 years) with episodic migraine who had previously been failed by two to four classes of conventional oral treatments for migraine prevention were randomly assigned (1:1) using interactive web response technology to oral atogepant 60 mg once a day or placebo, stratified by baseline monthly migraine days, number of treatment classes participants have been failed by, and region. The primary endpoint was change from baseline in mean monthly migraine days across the 12-week treatment period in the off-treatment hypothetical estimand (OTHE) population, which included participants in the safety population (all participants who received ≥1 dose of study intervention) who had evaluable data available for the baseline period and for one or more of the 4-week post-baseline periods (whether on treatment or off treatment). The primary endpoint was analysed using a mixed model for repeated measures and a fixed-sequence procedure was used to control for multiple comparisons. The trial is registered with ClinicalTrials.gov (NCT04740827) and EudraCT (2019-003448-58), and is completed.

FINDINGS

Between March 5, 2021, and Aug 4, 2022, 540 participants were screened, 315 were randomly assigned, and 313 participants (280 [89%] female, 33 [11%] male, and 300 [96%] White) received at least one dose of study intervention. In the OTHE population, which comprised 309 participants (155 assigned to placebo and 154 to atogepant), least squares mean changes from baseline in monthly migraine days across 12 weeks were -1·9 (SE 0·4) with placebo and -4·2 (0·4) with atogepant (least squares mean difference -2·4, 95% CI -3·2 to -1·5; adjusted p<0·0001). The most common treatment-emergent adverse event with atogepant was constipation in 16 (10%) of 156 participants (vs four [3%] of 157 for placebo). Serious adverse events occurred in four [3%] of 156 participants in the atogepant group vs none in the placebo group, and treatment-emergent adverse events resulting in treatment discontinuation occurred in three [2%] in the atogepant group vs two [1%] in the placebo group.

INTERPRETATION

Atogepant 60 mg once a day was safe, well tolerated, and showed significant and clinically relevant reductions in mean monthly migraine days compared with placebo across 12 weeks in patients with episodic migraine who had previously been failed by two to four classes of conventional oral preventive treatments. Atogepant might be an effective preventive treatment option for patients in this difficult-to-treat population.

FUNDING

Allergan (now AbbVie).

Effects of OnabotulinumtoxinA on Allodynia and Interictal Burden of Patients with Chronic Migraine

BACKGROUND

We primarily aimed to ascertain whether treatment with OnabotulinumtoxinA (BoNTA) might influence the extent of the interictal burden and cutaneous allodynia in patients with chronic migraine (CM).

METHODS

Seventy CM patients, who received three consecutive cycles of BoNTA, were studied. The interictal burden was assessed with the Migraine Interictal Burden Scale (MIBS-4), while cutaneous allodynia was examined with the Allodynia Symptom Checklist (ASC-12) together with PI-NRS VAS to obtain hair brushing scores, and then these were compared from baseline (T0) to the last efficacy evaluation follow-up (T1). Efficacy outcomes, mostly mean headache days (MHD) and "Headache Impact Test" scores, were also assessed between T0 and T1.

RESULTS

BONTA improved the interictal burden, with a decrease in MIBS-4 scoring by an average of -7 at T1, compared to baseline (p < 0.001). The percentage of patients with a moderate/severe interictal burden was substantially decreased. Likewise, BoNTA reduced the extent of cutaneous allodynia, with a significant reduction in both the ASC-12 (1 vs. 6; p < 0.001) and PI-NRS VAS (1 vs. 5; p < 0.001) to hair brushing median scores at T1, compared to baseline. Reduced MHD rates were significantly associated with a smaller interictal burden at T1. The efficacy of BoNTA, with a significant reduction in MHD and HIT-6 scores at T1 compared to T0, was re-confirmed.

CONCLUSIONS

BoNTA resulted in a statistically significant reduction in the interictal burden and also improved cutaneous allodynia. The reduction in ictal burden was associated with the down-scaling of the interictal burden. Hence, BoNTA improved the full spectrum of migraine impairment by diminishing the clinical expression of central sensitization.