Identifying Natural Subgroups of Migraine Based on Comorbidity and Concomitant Condition Profiles: Results of the Chronic Migraine Epidemiology and Outcomes (CaMEO) Study

An Integrative Migraine Polygenic Risk Score Is Associated with Age at Onset But Not Chronification

Background/Objective: Genome-wide association studies (GWASs) demonstrate a complex genetic landscape for migraine risk. Migraine polygenic risk scores (PRSs) developed from GWAS data may have utility for predicting disease course. We analyzed the strength of association between an integrative migraine PRS and age at onset and chronification. Methods: In this retrospective clinical/genetic case-control study, PGS004799 was calculated for adults with European ancestry from two real-world community cohorts. In the DodoNA cohort, 1653 treated, deeply phenotyped migraine cases, diagnosed using International Classification of Headache Disorders 3rd edition criteria, were followed for a mean (range) of 2.3 (1-10) years and compared to 3460 controls (without migraine diagnosis). In the GHI cohort, 2443 cases were identified using the first migraine ICD code as a proxy for migraine onset and compared to 8576 controls (without migraine ICD codes). PRS associations with age at onset (DodoNA) or first migraine ICD code (GHI) and chronification (DodoNA) were evaluated. Results: In both cohorts, PRS was higher in cases (DodoNA mean (range) cases: 0.82 (0.07-1.76), controls: 0.78 (0.04-1.56); t (5111) = -6.1, p = 1.4 × 10-9, GHI: cases: 0.79 (0.003-1.68), controls: 0.75 (-0.06-1.53); t (11,017) = -7.69, p = 1.6 × 10-14), and a higher PRS was associated with earlier onset in females (HR [95% CI] DodoNA: 2.1 [1.6-2.6, p < 0.001; GHI: 1.8 [1.4-2.1], p < 0.001) and in males (DodoNA: 2.5 [1.3-4.7], p = 0.005; GHI: 1.6 [1.1-2.6], p = 0.027). PRS was not different in cases with or without chronification (t (1651) = -1.67, p = 0.094) and was not associated with earlier chronification (1.2 [0.8-1.6], p = 0.424). Conclusions: Higher genetic risk was associated with earlier onset and increased risk of migraine well into adulthood, but not with chronification. This suggests that the PRS quantifies genetic susceptibility that is distinct from factors influencing disease course.

Latent class analysis of migraine associated vestibular-auditory symptoms

OBJECTIVE

This study aimed to identify the potential subgroups of migraines based on the patterns of migraine associated symptoms, vestibular and auditory symptoms using latent class analysis and to explore their characteristics.

METHOD

A total of 555 patients with migraine participated in the study. Symptoms such as nausea, vomiting, photophobia, phonophobia, osmophobia, visual symptoms, vestibular symptoms (dizziness, vertigo), and auditory symptoms (tinnitus, hearing loss, aural fullness) were assessed. Latent class analysis was performed to identify subgroups of migraines. Covariates such as gender, age of migraine onset, frequency of migraine attacks per month, and family history were also considered.

RESULTS

The analysis revealed four latent classes: the Prominent Vestibular; Prominent Nausea; Presenting Symptoms but not prominent or dominant; and Sensory Hypersensitivity groups. Various covariates, such as gender, age of migraine onset, and frequency of migraine attacks, demonstrated significant differences among the four groups. The Sensory Hypersensitivity group showed the presence of multiple sensory symptoms, earlier age of migraine onset, and higher proportion of females. The Prominent Vestibular group had the highest probability of dizziness or vertigo but lacked the presence of auditory symptoms. The Prominent Nausea group exhibited prominent nausea. The Presenting Symptoms but not prominent or dominant group comprised individuals with the highest migraine attacks per month and proportion of chronic migraine.

CONCLUSION

This study identifies four subgroups of migraines based on the patterns of symptoms. The findings suggest potential different but overlapped mechanisms behind the vestibular and auditory symptoms of migraine. Considering the different patterns of migraine-related symptoms may provide deeper insights for patients' prognosis and clinical decision-making.

Photophobia is associated with lower sleep quality in individuals with migraine: results from the American Registry for Migraine Research (ARMR)

BACKGROUND

Patients with migraine often have poor sleep quality between and during migraine attacks. Furthermore, extensive research has identified photophobia as the most common and most bothersome symptom in individuals with migraine, second only to headache. Seeking the comfort of darkness is a common strategy for managing pain during an attack and preventing its recurrence between episodes. Given the well-established effects of daily light exposure on circadian activity rhythms and sleep quality, this study aimed to investigate the relationship between photophobia symptoms and sleep quality in a cohort of patients with migraine.

METHODS

A cross-sectional observational study was conducted using existing data extracted from the American Registry for Migraine Research (ARMR). Participants with a migraine diagnosis who had completed the baseline questionnaires (Photosensitivity Assessment Questionnaire (PAQ), Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-2 (PHQ-2)), and selected questions of the ARMR Sleep questionnaire were included. Models were created to describe the relationship of photophobia and photophilia with various sleep facets, including sleep quality (SQ), sleep disturbance (SDis), sleep onset latency (SOL), sleep-related impairments (SRI), and insomnia. Each model was controlled for age, sex, headache frequency, anxiety, and depression.

RESULTS

A total of 852 patients meeting the inclusion criteria were included in the analysis (mean age (SD) = 49.8 (13.9), 86.6% (n = 738) female). Those with photophobia exhibited significantly poorer sleep quality compared to patients without photophobia (p < 0.001). Photophobia scores were associated with SQ (p < 0.001), SDis (p < 0.001), SOL (p = 0.011), SRI (p = 0.020), and insomnia (p = 0.005) after controlling for age, sex, headache frequency, depression, and anxiety, signifying that higher levels of photophobia were associated with worse sleep-related outcomes. Conversely, photophilia scores were associated with better sleep-related outcomes for SQ (p < 0.007), SOL (p = 0.010), and insomnia (p = 0.014).

CONCLUSION

Results suggest that photophobia is a significant predictor of poor sleep quality and sleep disturbances in migraine. These results underscore the necessity for comprehensive and systematic investigations into the intricate interplay between photophobia and sleep to enhance our understanding and develop tailored solutions for individuals with migraine.

Clinical features of migraine with aura: a REFORM study

BACKGROUND

About one-third of persons with migraine experience transient neurologic symptoms, referred to as aura. Despite its widespread prevalence, comprehensive clinical descriptions of migraine with aura remain sparse. Therefore, we aimed to provide an in-depth phenotypic analysis of aura symptoms and characteristics in a cross-sectional study of a large sample of adults diagnosed with migraine with aura.

METHODS

Data were extracted from the baseline characteristics of participants in the Registry for Migraine (REFORM) study - a single-center, prospective, longitudinal cohort study. Participants were adults diagnosed with migraine aura, reporting ≥ 4 monthly migraine days in the preceding 3 months. Trained personnel conducted in-person semi-structured interviews, capturing details on the nature, duration, localization, and progression of individual aura symptoms.

RESULTS

Of the 227 enrolled participants with migraine with aura, the mean age was 41.1 years, with a predominant female representation (n = 205 [90.3%]). Visual aura was present in 215 (94.7%) participants, somatosensory aura in 81 (35.7%), and speech and/or language aura in 31 (13.7%). A single type of aura was observed in 148 (65.2%) participants, whilst 79 (34.8%) reported multiple aura types. Most participants (n = 220 [96.9%]) described their aura symptoms as positive or gradually spreading. Headache in relation to aura was noted by 218 (96.0%) participants, with 177 (80.8%) stating that the onset of aura symptoms preceded the onset of headache.

CONCLUSIONS

This study offers a detailed clinical depiction of persons with migraine with aura, who were predominantly enrolled from a tertiary care unit. The findings highlight potential gaps in the available literature on migraine with aura and should bolster clinicians' acumen in diagnosing migraine with aura in clinical settings.

Comorbid conditions in Egyptian patients with migraine

BACKGROUND

Identifying migraine comorbidities may guide prognosis and treatment options. This study aimed to assess the frequency of comorbid conditions among adults with migraine living in Greater Cairo.

METHODS

In this cross-sectional study, Egyptian migraine sufferers aged ≥ 18 years living in Greater Cairo were consecutively recruited (April 2019 - April 2021). Following The International Classification of Headache Disorders-third edition, diagnosis of migraine was confirmed, and the type of migraine was defined as whether episodic or chronic, with or without aura, with childhood/adolescence or adulthood onset. Specialist physicians from the research team assessed comorbid conditions among the respondents.

RESULTS

The mean age of respondents (n = 1064) was 35 ± 7. Irritable bowel syndrome represented the most common comorbidity in our patients (45.5%), followed by vitamin D deficiency (41.8%). The frequency of epilepsy, stroke, multiple sclerosis, and systemic lupus erythematosus was significantly higher in patients with chronic than episodic type (χ2 = 4.514, P = 0.034), (χ2 = 12.302, P = 0.001), (χ2 = 12.302, P = 0.001), (χ2 = 4.806, P 0.028), respectively. Females with menstrual migraines had a significantly higher frequency of generalized anxiety disorder, panic attacks, and restless leg syndrome than those with non-menstrual migraines (χ2 = 7.636, P 0.006), (χ2 = 9.245, P = 0.002), and (χ2 = 11.997, P = 0.001), respectively. The frequency of diabetes was significantly higher in patients with migraine with aura than in those without aura (χ2 = 4.248, P value 0.039).

CONCLUSION

This study provides a better understanding of the comorbidities in Egyptian patients with migraine and will provide new avenues for developing individualized therapy for migraine patients.

New management strategies for primary headache disorders: Insights from P4 medicine

Primary headache disorder is the main cause of headache attacks, leading to significant disability and impaired quality of life. This disorder is increasingly recognized as a heterogeneous condition with a complex network of genetic, environmental, and lifestyle factors. However, the timely diagnosis and effective treatment of these headaches remain challenging. Precision medicine is a potential strategy based on P4 (predictive, preventive, personalized, and participatory) medicine that may bring new insights for headache care. Recent machine learning advances and widely available molecular biology and imaging data have increased the usefulness of this medical strategy. Precision medicine emphasizes classifying headaches according to their risk factors, clinical presentation, and therapy responsiveness to provide individualized headache management. Furthermore, early preventive strategies, mainly utilizing predictive tools, are critical in reducing headache attacks and improving the quality of life of individuals with headaches. The current review comprehensively discusses the potential application value of P4 medicine in headache management.

Evaluating therapeutic benefits of ubrogepant via latent class models: A post hoc exploratory analysis of the ACHIEVE I and ACHIEVE II trials

OBJECTIVE

To evaluate an alternative method of defining acute treatment success in migraine by combining multiple indicators into a single dichotomous measure of success.

BACKGROUND

Migraine is characterized by a symptom complex; combining these features as a single endpoint may improve the measurement of treatment effects and better predict patient satisfaction with treatment.

METHODS

We used a confirmatory latent class model (LCM) with two latent classes interpreted as treatment success and treatment failure. Pooled data for placebo and ubrogepant 50 mg from the ACHIEVE I and ACHIEVE II trials and data for ubrogepant 100 mg from ACHIEVE I were used. LCM inputs included pre-dose and 2-h post-dose measures of pain severity (0-3), the presence/absence of associated symptoms (nausea, photophobia, and phonophobia [0 or 1]), and functional disability (0-3). All definitions were validated against satisfaction with study medication (SWSM) at 24 h post-dose; results were compared with 2-hour pain freedom (2hPF).

RESULTS

This pooled analysis included 2247 participants. At 2 h post-dose in the ubrogepant 50 and 100 mg dose groups, 53.2% (472/887) and 54.9% (246/448) of participants, respectively, were classified as achieving treatment success using the LCM-based approach, compared to 39.0% (356/912) of participants in the placebo group. The results for treatment success using the 2hPF endpoint were 20.7% (184/887) and 21.5% (96/447) in the ubrogepant 50 and 100 mg dose groups, respectively, compared to 12.7% (116/912) for placebo. Using 24-h SWSM as an external validator, the LCM approach sensitivity and correct classification rates were higher than for 2hPF.

CONCLUSION

The LCM approach led to higher rates of treatment success and greater separation between ubrogepant and placebo and was a more sensitive predictor of treatment satisfaction than the regulatory endpoint of 2hPF.

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

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

Towards precision medicine in migraine: Recent therapeutic advances and potential biomarkers to understand heterogeneity and treatment response

After 35 years since the introduction of the International Classification of Headache Disorders (ICHD), we are living in the era of the second great revolution in migraine therapies. First, discoveries of triptans provided a breakthrough in acute migraine treatment utilizing bench-to-bedside research results on the role of serotonin in migraine. Next, the discovery of the role of neuropeptides, more specifically calcitonin gene-related peptide (CGRP) in migraine attack led to the development of anti-CGRP therapies that are effective both in acute and preventive treatment, and are also able to reduce migraine-related burden. Here, we reviewed the most recent clinical studies and real-world data on available migraine-specific medications, including triptans, ditants, gepants and anti-CGRP monoclonal antibodies. Novel drug targets, such as PACAP and amylins were also discussed. To address the main challenges of migraine therapy, the high heterogeneity of people with migraine, the prevalent presence of various comorbid disorders, and the insufficient medical care of migraine patients were covered. Promising novel approaches from the fields of omics, blood and saliva biomarker, imaging and provocation studies might bring solutions for these challenges with the potential to identify further drug targets, distinguish more homogeneous patient subgroups, contribute to more optimal drug selection strategies, and detect biomarkers in association with headache features or predicting treatment efficacy. In the future, the combined analysis of data of different biomarker modalities with machine learning algorithms may serve precision medicine in migraine treatment.

Profiling migraine patients according to clinical and psychophysical characteristics: a cluster analysis approach

AIM

This study aims to profile migraine patients according clinical and psychophysical characteristics.

METHOD

In this observational study, two cohorts of migraine patients(episodic/chronic) were included. Cohort-1: ictal/perictal phase; Cohort-2: interictal phase.The following variables were assessed: headache frequency; disability; cervical active range of motion(AROM) in flexion, extension, right/left lateral flexion, right/left rotation; pressure-pain threshold(PPT) over: temporalis, two cervical areas(C1/C4 vertebral segments), and two distal pain-free areas(hand/leg). Cluster analysis was performed using the K-means algorithm. Differences across clusters were investigated.

RESULTS

Cohort-1: 100 patients were included, and two clusters were identified. Cluster-1.1 (19%), Cluster-1.2 (81%). Cluster 1.1 had a higher percentage of men (P = .037) and higher disability (P = .003) compared to Clusters 1.2. Cluster 1.2 had reduced AROM in flexion, extension, and left/right lateral flexion (P < .037), and lower PPT value in all areas (P < .001) compared to Cluster 1.1. Cohort-2: 98 patients were included and three clusters were identified. Cluster-2.1(18%), Cluster-2.2(45%), and Cluster-2.3(37%). Cluster-2.1 had a higher percentage of men compared to clusters-2.2 and 2.3 (P = .009). Cluster-2.3 had higher headache frequency, and disability compared to Cluster-2.2 (P < .006), and higher disability compared to Cluster-2.1 (P = .010). Cluster-2.3 had reduced AROM in all directions compared to Clusters-2.1 and 2.2 (P < .029). Clusters-2.2 and 2.3 have lower PPT values in all areas compared to Cluster-1.1 (P < .001).

CONCLUSION

In the Ictal/perictal phase, two clusters were identified according to clinical and psychophysical characteristics, with one group showing no psychophysical impairment and one with increased pain-sensitivity and cervical musculoskeletal-dysfunctions.In the interictal phase, three clusters could be identified, with one group showing no psychophysical impairment, one increased pain-sensitivity, and one increased pain sensitivity and cervical musculoskeletal-dysfunctions.

The effect of sex and estrus cycle stage on optogenetic spreading depression induced migraine-like pain phenotypes

BACKGROUND

Migraine is more prevalent in females, raising the possibility that sex and gonadal hormones modulate migraine. We recently demonstrated that minimally invasive optogenetic spreading depolarization (opto-SD) elicits robust periorbital allodynia. The objective of this study was to test the hypothesis that opto-SD induced migraine-like pain behavior is worse in females and varies during the estrus cycle.

METHODS

Single or repeated opto-SDs were induced in male and female adult Thy1-ChR2-YFP transgenic mice. Von Frey monofilaments were used to test periorbital mechanical allodynia. Mouse grimace was also examined under increasing light intensity to quantify spontaneous discomfort and light-aversive behavior. Vaginal smears were obtained for estrus cycle staging at the end of behavioral testing.

RESULTS

A multi-variable regression analysis was performed using a male and female cohort to test the effect of independent variables on periorbital allodynia. Opto-SD predicted lower periorbital thresholds as compared with sham stimulation (p < 0.0001). Additionally, female sex predicted lower periorbital thresholds compared with males (p = 0.011). There were significant interactions between opto-SD and time (interaction p = 0.030) as animals tended to recover from opto-SD allodynia over time, and between sex and time (p = 0.020) as females tended to take longer to recover. Proestrus, estrus (PE) and metestrus, diestrus (MD) stages were combined to represent high versus low circulating estradiol relative to progesterone, respectively. Multi-variable regression revealed an effect of estrus cycle (p = 0.015) on periorbital thresholds. In the sham group, PE had lower thresholds than MD. However, there was no interaction between opto-SD and the estrus cycle (p = 0.364). Grimace scores were also examined at incremental light intensities. There was an effect of opto-SD (p < 0.0001), light intensity (p = 0.001) and estrus cycle (p = 0.024) on grimace without interaction among them (three-way ANOVA).

CONCLUSIONS

Female sex and estrus stages with high circulating estradiol relative to progesterone lower trigeminal pain thresholds and augment photosensitivity. In females, opto-SD increased pain behavior and photosensitivity irrespective of the estrus stage.

Burden of migraine with acute medication overuse or psychiatric comorbidities and treatment with CGRP pathway-targeted monoclonal antibodies: A review

Migraine is a complex and often debilitating neurological disease that affects more than 1 billion people worldwide. It is characterized by moderate-to-intense, throbbing headache attacks that are worsened by activity and is associated with nausea, vomiting, and sensitivity to light and sound. Migraine, ranked the second leading cause of years lived with disability by the World Health Organization, can diminish patients' quality of life and bring significant personal and economic burden. Furthermore, migraine patients with a history of acute medication overuse (AMO) or psychiatric comorbidities, such as depression or anxiety, may experience even greater impairment and burden, and their migraine may be more difficult-to-treat. Appropriate treatment of migraine is essential to reduce this burden and improve patient outcomes, especially for those with AMO or psychiatric comorbidities. There are several available preventive treatment options for migraine, though many of these are not migraine-specific and may have limited efficacy and/or poor tolerability. The calcitonin gene-related peptide pathway plays a key role in the pathophysiology of migraine, and monoclonal antibodies that target the calcitonin gene-related peptide pathway have been developed as specific preventive treatments for migraine. Four of these monoclonal antibodies have been approved for the preventive treatment of migraine after demonstrating favorable safety and efficacy profiles. These treatments offer substantial benefits for migraine patients, including those with AMO or common psychiatric comorbidities, by reducing monthly headache days and migraine days, days of acute medication use, and disability measures, as well as improving quality of life.

Genetics of migraine: Delineation of contemporary understanding of the genetic underpinning of migraine

Migraine is a disabling episodic brain disorder with an increased familial relative risk, an increased concordance in monozygotic twins, and an estimated heritability of approximately 50%. Various genetic approaches have been applied to identify genetic factors conferring migraine risk. Initially, candidate gene associations studies (CGAS) have been performed that test DNA variants in genes prioritized based on presumed a priori knowledge of migraine pathophysiology. More recently, genome-wide association studies (GWAS) are applied that test genetic variants, single-nucleotide polymorphisms (SNPs), in a hypothesis-free manner. To date, GWAS have identified ~40 genetic loci associated with migraine. New GWAS data, which are expected to come out soon, will reveal over 100 loci. Also, large-scale GWAS, which have appeared for many traits over the last decade, have enabled studying the overlap in genetic architecture between migraine and its comorbid disorders. Importantly, other genetic factors that cannot be identified by a GWAS approach also confer risk for migraine. First steps have been taken to determine the contribution of these mechanisms by investigating mitochondrial DNA and epigenetic mechanisms. In addition to typical epigenetic mechanisms, that is, DNA methylation and histone modifications, also RNA-based mechanisms regulating gene silencing and activation have recently gotten attention. Regardless, until now, most relevant genetic discoveries related to migraine still come from investigating monogenetic syndromes with migraine as a prominent part of the phenotype. Experimental studies on these syndromes have expanded our knowledge on the mechanisms underlying migraine pathophysiology. It can be envisaged that when all (epi)genetic and phenotypic data on the common and rare forms of migraine will be integrated, this will help to unravel the biological mechanisms for migraine, which will likely guide decision-making in clinical practice in the future.

Comorbidities in patients with migraine in Japan: a cross-sectional study using data from National Health and Wellness Survey

OBJECTIVES

This study aims to examine the association between migraine and various psychiatric and somatic comorbidities in Japan.

DESIGN

Cross-sectional study using existing data of the 2017 Japan National Health and Wellness Survey (NHWS).

SETTING

Nationally representative sample of persons (in terms of age and gender) living in the general community aged 18 years or older in Japan.

PARTICIPANTS

Out of a sample of 30 001 NHWS respondents, 378 respondents were identified as migraine patients and 25 209 were identified as non-migraine patients. After propensity score (PS) matching (1:4), 1512 matched non-migraine respondents were identified.

PRIMARY AND SECONDARY OUTCOME MEASURES

Prevalence and PS-matched prevalence ORs (PORs) were assessed for each psychiatric and somatic comorbidity among migraine patients and matched non-migraine respondents (including migraine patients with less than 15 monthly headache days (MHDs) and migraine patients with more than 15 MHDs).

RESULTS

Migraine patients were predominately female and had significantly higher prevalence than matched non-migraine respondents to have psychiatric and somatic comorbidities. Psychiatric comorbidities with >5% prevalence among migraine patients included depression, post-traumatic stress disorder and anxiety disorders, while gastrointestinal disorders were the most prevalent somatic comorbidity category. Other somatic comorbidities included allergies, insomnia, premenstrual syndrome and anaemia. Migraine patients with more than 15 MHDs tended to have higher point estimates for POR.

CONCLUSION

Psychiatric and somatic conditions were more prevalent in migraine patients than matched non-migraine respondents, some being novel associations not previously reported in Japan. This study provided insights on comorbidities, which could complicate care, clinical practice and outcomes among migraine patients.

A population-health approach to characterizing migraine by comorbidity: Results from the Mindfulness and Migraine Cohort Study

BACKGROUND

The heterogeneity of migraine has been reported extensively, with identified subgroups usually based on symptoms. Grouping individuals with migraine and similar comorbidity profiles has been suggested, however such segmentation methods have not been tested using real-world clinical data.

OBJECTIVE

To gain insights into natural groupings of patients with migraine using latent class analysis based on electronic health record-determined comorbidities.

METHODS

Retrospective electronic health record data analysis of primary-care patients at Sutter Health, a large open healthcare system in Northern California, USA. We identified migraine patients over a five-year time period (2015-2019) and extracted 29 comorbidities. We then applied latent class analysis to identify comorbidity-based natural subgroups.

RESULTS

We identified 95,563 patients with migraine and found seven latent classes, summarized by their predominant comorbidities and population share: fewest comorbidities (61.8%), psychiatric (18.3%), some comorbidities (10.0%), most comorbidities - no cardiovascular (3.6%), vascular (3.1%), autoimmune/joint/pain (2.2%), and most comorbidities (1.0%). We found minimal demographic differences across classes.

CONCLUSION

Our study found groupings of migraine patients based on comorbidity that have the potential to be used to guide targeted treatment strategies and the development of new therapies.

Post-COVID-19 neuropsychiatric manifestations among COVID-19 survivors suffering from migraine: a case-control study

BACKGROUND

The burden of post-coronavirus disease (COVID)-19 symptoms has been increasing and is of great concern in patients with pre-existing chronic medical conditions.This study aimed to delineate the post-COVID-19 neuropsychiatric symptoms among migraine patients compared to the non-migraine control group.

METHODS

Two groups, each of 204 COVID-19 survivors, were enrolled in the study after 3 months of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, one group fulfilling the episodic migraine criteria and the other serving as a matching control group. Subjects were evaluated through an in-person interview for post-COVID-19 neuropsychiatric symptoms, including detailed headache patterns and severity, using the visual analogue scale.

RESULTS

The Frequency of headache during the acute phase of COVID-19 was more frequent in migraine patients (OR = 1.60, 95%CI = 1.04-2.45, P-value = 0.031). The reported significant post-COVID-19 neuropsychiatric symptoms in migraine patients compared to controls were fatigue (OR = 1.662, 95%CI = 1.064-2.596, P-value = 0.025), anosmia/hyposmia (OR = 2.06, 95%CI = 1.164- 3.645, P-value = 0.012), cacosmia (OR = 2.663, 95%CI = 1.145-6.195, P-value = 0.019), depression (OR = 2.259, 95%CI = 1.284- 3.975, P-value = 0.004), anxiety (OR = 3.267, 95%CI = 1.747- 6.108, P-value ≤ 0.001), insomnia (OR = 2.203, 95%CI = 1.298- 3.739, P-value = 0.003), and headache (OR = 3.148, 95%CI = 1.616-6.136, P-value =  ≤ 0.001).While there was no statistically significant difference between migraine patients and controls regarding the post-COVID-19 functional status score (P-value = 0.102). The pattern of post-COVID-19 headache was reported as chronic headache transformation in 17.6% of the migraine group, with the median intensity rate being 5.5 and IQR (3-7). In the control group, 14% experienced chronic headache attributed to systemic viral infection with a median intensity rate of 2 and IQR (2-5), while 12% experienced a new daily persistent headache with a median intensity of 5 and IQR (1-6).

CONCLUSION

The study highlighted the importance of follow-up migraine patients upon recovery from COVID-19 infection, being more vulnerable to post-COVID-19 symptoms.

Association of a Cyclical Migraine Phenotype With Disease Progression: A One-Year Time Series Analysis

OBJECTIVE

Longitudinal studies assessing cyclic fluctuations of migraine attacks using time-series analysis are scarce. Here we analyze headache frequency fluctuations over a year in a cohort of migraine patients and we then evaluate how this behaviour has an impact on clinical evolution.

METHODS

Monthly headache frequency was prospectively collected using an eDiary. Prognosis after one year was calculated as the headache frequency change rate after 12 months (HCR-M12) as a dependent variable. Monthly headache time series was decomposed into all the possible sum of sinusoids through a Fast Fourier Transform algorithm (FFT) and the frequencies with the highest power were used to define the patient's cyclic phenotype during one year (patient's number of cycles per year, c/y). Patients with a cyclic phenotype were those with >2 cycles/year. Finally, we studied how this cyclic phenotype was associated to HCR-M12 using Generalized Linear Models (GLM).

RESULTS

142 patients were included (85.2% female; mean age 48.0±9.7 years), 50.0% fulfilled IHCD-3 criteria for chronic migraine (CM). After one year, a 50.7% (72/142) of patients changed their initial diagnosis and progression (frequency worsening) was observed in 14.1% (10/71) of episodic migraine (EM) patients. After applying a FFT, 45.1% (64/142) of patients fitted into a cyclic phenotype. In GLM, statistically significant main effects associated to HCR-M12 were the use of preventive therapy (Beta [SE]: 74.1 [34.6]; p=0.034) and cyclic phenotype (Beta [SE]: 158.33 [55.1]; p=0.005). A post-hoc analysis found that EM patients with cyclic phenotype without adequate preventive therapy were statistically significantly associated to progression.

CONCLUSIONS

Monthly headache frequency data can be fitted by sinusoidal models. Having a cyclic phenotype has an impact on clinical evolution and has been statistically significantly associated to migraine progression after one year. Particularly, EM patients with cyclic phenotype tend to increase their headache frequency over time. Preventive treatment seems to play a fundamental role in modulating this cyclic behaviour, especially in low-frequency EM patients.

Microstructural white matter changes in chronic migraine patients with liver-yang hyperactivity and qi-blood deficiency syndrome: a diffusion tensor imaging study

White matter alterations in patients with chronic migraine (CM) have been reported. Traditional Chinese medicine (TCM) syndromes are clinical syndromes proposed by TCM doctors based on long-term clinical observation and classification of the clinical symptoms and signs of CM patients. This study aimed to analyze the whole-brain diffusion tensor imaging (DTI) data of CM patients with different types of TCM syndromes. Sixteen CM patients diagnosed with liver-yang hyperactivity (LH) syndrome and 16 CM patients with qi-blood deficiency (QD) syndrome were recruited in this study. Thirty-one healthy controls (HCs) were also enrolled. All subjects underwent DTI and T1-weighted MRI acquisition. Thirty HCs and 30 CM patients (LH group: n = 15; QD group: n = 15) were included in the final analysis. No significant difference was observed in the DTI indexes between CM patients and HCs, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). The mean FAs of the left tapetum and the mean MD values for the right medial lemniscus and the right inferior cerebellar peduncle were significantly different in the LH and HC groups. The mean AD values for the right cingulate gyrus and the left uncinate fasciculus, as well as the mean RD for the right inferior cerebellar peduncle and the left tapetum, were also significantly different between these two groups. CM patients with LH and QD syndrome showed altered FA and diffusivity in comparison to healthy controls, suggesting that there may be significant white matter microstructural alterations in these patients.

Population-based prevalence of cranial autonomic symptoms in migraine and proposed diagnostic appendix criteria

BACKGROUND

Migraine with cranial autonomic symptoms is well described in the literature, but its prevalence in previous studies varies enormously. A precise estimate of the prevalence in a population-based material is important because migraine with cranial autonomic symptoms might represent an endophenotype, in which genetic and pathophysiological features differ from those without cranial autonomic features. The aim of the present study, therefore, was to estimate the prevalence in a big population-based sample using both questionnaire-based diagnosis (N = 12,620) and interview-based diagnosis (N = 302). We validate questionnaire-based diagnosis of migraine with cranial autonomic symptoms and develop the first diagnostic criteria for future research of this possible endophenotype.

METHODS

The Danish Blood Donor Study included 127,802 persons who all received a migraine diagnostic questionnaire. Participants who had answered the diagnostic questionnaire constituted the Danish Migraine Population Cohort (N = 62,677) of whom 12,620 had migraine. The diagnostic migraine questionnaire included questions about the following cranial autonomic symptoms: Facial/forehead sweating, lacrimation, ptosis, conjunctival injection, rhinorrhea, nasal congestion, and miosis. Validation was performed by a follow-up semi-structured, purpose-built interview of 302 participants with migraine, where detailed questions were asked to ascertain the validity of the symptoms.

RESULTS

The questionnaire-based prevalences of one, respectively two cranial autonomic symptoms were 57% and 31%. The semi-structured interview-based prevalences of one, respectively two symptoms were 44% and 22%. The most common symptoms were facial/forehead sweating (39%) and lacrimation (24%). The specificity of the questionnaire was 80% and the sensitivity was 68%. Correlation analysis showed a weak correlation between symptoms ranging from 0.07 - 0.41, and no clear clustering of symptoms was detected. We suggest the first diagnostic appendix criteria for genetic and epidemiological studies and tighter criteria for clinical and pathophysiological studies. We encourage further studies of severity and consistency of symptoms.

CONCLUSION

Migraine with cranial autonomic symptoms is prevalent in the general population. Suggested diagnostic appendix criteria are important for future studies of this possible migraine endophenotype.

A Markov Analysis of Surgical versus Medical Management of Chronic Migraines

BACKGROUND

Refractory chronic migraine is a common and debilitating neurologic condition, affecting over 8 million people in the United States. It is associated with billions of dollars in lost productivity annually. Novel medical (anti-calcitonin gene-related peptide antibodies) and surgical treatment modalities have emerged for chronic migraine in recent years. The current study investigated the cost-utility of surgical versus medical management of refractory chronic migraine.

METHODS

A Markov cohort analysis using hybrid Monte Carlo patient simulation was performed to compare surgical decompression versus erenumab for the treatment of refractory chronic migraine in adults. Both societal and payer perspectives were considered. Primary model outcomes included incremental cost-effectiveness ratio, or cost per quality-adjusted life-year gained.

RESULTS

Over a 5-year period, migraine surgery was associated with an increase of 0.2 quality-adjusted life-year per patient when compared to erenumab. In terms of costs, the results demonstrated a $19,337 decrease in direct medical costs and a $491 decrease in indirect costs (productivity lost) for the surgery cohort compared to erenumab. Because surgery improved quality of life and decreased costs compared to erenumab, even when considering revision surgery needs, surgery was the overall dominant treatment in terms of cost-effectiveness. Sensitivity analyses demonstrated that surgery was cost-effective compared to erenumab when patients required therapy for at least 1 year.

CONCLUSIONS

Surgical deactivation of migraine trigger sites may pose a cost-effective approach to treating refractory chronic migraine in adults. This is especially the case when patients are anticipated to require therapy for more than 1 year.

Headache as a Neurologic Manifestation of Systemic Disease

Purpose of Review

Recent Findings

Summary

Prevalence of trigeminocervical convergence mechanisms in episodic and chronic migraine

BACKGROUND

Migraine pain location and trigeminocervical convergence have limited diagnostic value and have usually been assessed using non-standard verbal descriptors in a small number of centers.

OBJECTIVE

To use non-verbal descriptors of migraine pain location to determine the prevalence of trigeminocervical convergence mechanisms in patients with episodic and chronic migraine. In addition, we explored the factors associated with the presence of convergence.

METHODS

A multicenter study was carried out. The explicit pain location was explored by asking subjects to indicate, on an electronic form, three points on the anterolateral side and three points on the posterolateral side of the head and neck that represented the common locations of their migraine pain. We evaluated associations of the pain pattern with demographic and psychological features, comorbidities, lifestyle and other headache characteristics.

RESULTS

97 episodic and 113 chronic migraine patients were included. Convergence was present in 116 migraineurs (55%) who indicated dominance of pain in the posterior cervical region. This site was more often involved in the chronic migraine group (21 vs. 33%; p=0.034). The number of migrainous/altered sensitivity symptoms (OR=1.39; 95%CI 1.14-1.71) was associated with convergence independently of the chronification status. In this symptom group, there were statistical associations between convergence and vomiting (p=0.045), tactile allodynia (p<0.001), nuchal rigidity (p<0.001) and movement allodynia (p=0.031).

CONCLUSIONS

Trigeminocervical convergence is common in migraineurs and, in practice, it might be found frequently in chronic migraineurs. Some features commonly found in this group, such as altered sensitivity symptoms, are associated with this phenomenon.

Cutaneous Allodynia in Migraine: A Narrative Review

Objective

In the present work, we conduct a narrative review of the most relevant literature on cutaneous allodynia (CA) in migraine.

Background

CA is regarded as the perception of pain in response to non-noxious skin stimulation. The number of research studies relating to CA and migraine has increased strikingly over the last few decades. Therefore, the clinician treating migraine patients must recognize this common symptom and have up-to-date knowledge of its importance from the pathophysiological, diagnostic, prognostic and therapeutic point of view.

Methods

We performed a comprehensive narrative review to analyze existing literature regarding CA in migraine, with a special focus on epidemiology, pathophysiology, assessment methods, risk for chronification, diagnosis and management. PubMed and the Cochrane databases were used for the literature search.

Results

The prevalence of CA in patients with migraine is approximately 60%. The mechanisms underlying CA in migraine are not completely clarified but include a sensitization phenomenon at different levels of the trigemino-talamo-cortical nociceptive pathway and dysfunction of brainstem and cortical areas that modulate thalamocortical inputs. The gold standard for the assessment of CA is quantitative sensory testing (QST), but the validated Allodynia 12-item questionnaire is preferred in clinical setting. The presence of CA is associated with an increased risk of migraine chronification and has therapeutic implications.

Conclusions

CA is a marker of central sensitization in patients with migraine that has been associated with an increased risk of chronification and may influence therapeutic decisions.

Headache outcomes of a sleep behavioral intervention in breast cancer survivors: Secondary analysis of a randomized clinical trial

BACKGROUND

Breast cancer survivors often have persisting headache. In a secondary analysis of the Brief Behavioral Therapy for Cancer-Related Insomnia (BBT-CI) clinical trial (ClinicalTrials.gov identifier NCT02165839), the authors examined the effects of BBT-CI on headache outcomes in patients with breast cancer.

METHODS

Patients with breast cancer who were receiving chemotherapy were randomly assigned to receive either the BBT-CI intervention or the Healthy EAting Education Learning for healthy sleep (HEAL) control intervention, and both were delivered over 6 weeks by trained staff. Headache outcomes and heart rate variability (HRV) were measured at baseline, 6 weeks, 6 months, and 12 months. Mixed-effects models were used to examine longitudinal headache outcomes in the groups according to the intention to treat. Principal component analysis and agglomerative hierarchical clustering were conducted to reduce 16 variables for data-driven phenotyping.

RESULTS

Patients in the BBT-CI arm (n = 73) exhibited a significant reduction in headache burden over time (P = .02; effect size [Cohen d] = 0.43), whereas the reduction was not significant among those in the HEAL arm (n = 66). The first principal component was positively loaded by headache, sleep, fatigue, and nausea/vomiting and was negatively loaded by cognitive, physical, and emotional functioning. Agglomerative hierarchical clustering revealed 3 natural clusters. Cluster I (n = 58) featured the highest burden of headache, insomnia, and nausea/vomiting; cluster II (n = 50) featured the lowest HRV despite a low burden of headache and insomnia; and cluster III (n = 31) showed an inverse relation between HRV and headache-insomnia, signifying autonomic dysfunction.

CONCLUSIONS

BBT-CI is efficacious in reducing headache burden in breast cancer survivors. Patient phenotyping demonstrates a headache type featuring sleep disturbance, nausea/vomiting, and low physical functioning-revealing similarities to migraine.

LAY SUMMARY

Breast cancer survivors often have persisting headache symptoms. In patients with cancer, treatment of chronic headache disorders using daily medications may be challenging because of drug interactions with chemotherapy and other cancer therapies as well as patients' reluctance to add more drugs to their medicine list. Headache and sleep disorders are closely related to each other. This study demonstrates that a sleep behavioral therapy reduced headache burden in breast cancer survivors. In addition, the majority of headache sufferers had a headache type with similarities to migraine-featuring sleep disturbance, nausea/vomiting, and low physical functioning.

Association between migraine and anxiety symptoms: Results from the study of women's health across the nation

BACKGROUND

This study aimed to examine the relationship between migraine and anxiety in US midlife women.

METHODS

This study was conducted on the baseline data from the Study of Women's Health Across the Nation (SWAN), a multi-site longitudinal population-based study of the US midlife women. Logistic regression was performed to assess the odds ratios (ORs) and 95% confidence intervals (CIs) between migraine and anxiety, adjusting for the main potential confounders.

RESULTS

A total of 3,302 midlife women aged from 42 to 52 with complete assessment of migraine and anxiety were enrolled. In both the crude model (OR: 1.47, 95% CI: 1.19-1.82, p < 0.001) and model 1 (OR: 1.31, 95% CI: 1.04-1.64, p = 0.022) indicated that anxiety was positive associated with migraine. After adjustment for age, ethnicity, family income, body mass index (BMI), smoking, alcohol drinking, physical activity, hypertension, diabetes, hypercholesterolemia, menopausal status, estradiol, dehydroepiandrosterone sulfate, follicle-stimulating hormone, sex hormone-binding globulin, testosterone, and thyroid stimulating hormone in full adjusted model 2, the association between migraine and anxiety remained statistically significant (OR: 1.28, 95% CI: 1.01-1.61, p = 0.038).

CONCLUSION

Migraine may be positively associated with anxiety in middle-aged women. Further large-scale prospective cohort studies are needed to investigate the causality between migraine and anxiety.

Classifying migraine subtypes and their characteristics by latent class analysis using data of a nation-wide population-based study

Migraine neither presents with a definitive single symptom nor has a distinct biomarker; thus, its diagnosis is based on combinations of typical symptoms. We aimed to identify natural subgroups of migraine based on symptoms listed in the diagnostic criteria of the third edition of the International Classification of Headache Disorders. Latent class analysis (LCA) was applied to the data of the Korean Sleep-Headache Study, a nationwide population-based survey. We selected a three-class model based on Akaike and Bayesian information criteria and characterized the three identified classes as “mild and low frequency,” “photophobia and phonophobia,” and “severe and high frequency.” In total, 52.0% (65/125) of the participants were classified as “mild and low frequency,” showing the highest frequency of mild headache intensity but the lowest overall headache frequency. Meanwhile, “photophobia and phonophobia” involved 33.6% (42/125) of the participants, who showed the highest frequency of photophobia and phonophobia. Finally, “severe and high frequency” included 14.4% (18/125) of the participants, and they presented the highest frequency of severe headache intensity and highest headache frequency. In conclusion, LCA is useful for analyzing the heterogeneity of migraine symptoms and identifying migraine subtypes. This approach may improve our understanding of the clinical characterization of migraine.

Hormonal influences in migraine - interactions of oestrogen, oxytocin and CGRP

Migraine is ranked as the second highest cause of disability worldwide and the first among women aged 15-49 years. Overall, the incidence of migraine is threefold higher among women than men, though the frequency and severity of attacks varies during puberty, the menstrual cycle, pregnancy, the postpartum period and menopause. Reproductive hormones are clearly a key influence in the susceptibility of women to migraine. A fall in plasma oestrogen levels can trigger attacks of migraine without aura, whereas higher oestrogen levels seem to be protective. The basis of these effects is unknown. In this Review, we discuss what is known about sex hormones and their receptors in migraine-related areas in the CNS and the peripheral trigeminovascular pathway. We consider the actions of oestrogen via its multiple receptor subtypes and the involvement of oxytocin, which has been shown to prevent migraine attacks. We also discuss possible interactions of these hormones with the calcitonin gene-related peptide (CGRP) system in light of the success of anti-CGRP treatments. We propose a simple model to explain the hormone withdrawal trigger in menstrual migraine, which could provide a foundation for improved management and therapy for hormone-related migraine in women.

Association between sleep and awake bruxism in patients with migraine

IntroductionWhen migraine undergoes transformation from episodic to chronic form it becomes more disabling due to the refractoriness in treatment and the emergence of comorbidities, with the establishment of a bidirectional relationship between sleep bruxism and chronic migraine. This study aimed to assess whether sleep and awake bruxism are more prevalent in chronic migraine when compared to episodic migraine and also to establish possible clinical correlations with the process of chronification.Methods210 patients were allocated to the study, 97 with episodic migraine and 113 with chronic migraine, who underwent face-to-face interviews with the completion of the scales: specific questionnaire for the diagnosis of sleep and awake bruxism, PHQ-9 (depression), GAD-7 (anxiety), Epworth Scale (daytime sleepiness), MIDAS (migraine incapacity) and HIT-6 (impact of headache). ResultsThe prevalence of sleep and awake bruxism was similar in patients with episodic versus chronic migraine (p = 0.300 and p = 0.238). The correlation of patients with concomitant awake and sleep bruxism and with high scores on the migraine incapacity (MIDAS) and headache impact (HIT-6) scales was higher among patients with chronic migraine than in patients with episodic migraine. (p <0.001 and p <0.001). ConclusionSleep and awake bruxism alone are not more prevalent in chronic migraine when compared to episodic migraine, although bruxism causes greater impact and disability on individuals with chronic migraine.

Neck Active Movements Assessment in Women with Episodic and Chronic Migraine

We aimed to compare movement parameters and muscle activity during active cervical spine movements between women with episodic or chronic migraine and asymptomatic control. We also assessed the correlations between cervical movement measures with neck-related disability and kinesiophobia. Women with episodic (n = 27; EM) or chronic (n = 27; CM) migraine and headache-free controls (n = 27; CG) performed active cervical movements. Cervical range of motion, angular velocity, and percentage of muscular activation were calculated in a blinded fashion. Compared to CG, the EM and CM groups presented a reduced total range of motion (p < 0.05). Reduced mean angular velocity of cervical movement was also observed in both EM and CM compared to CG (p < 0.05). Total cervical range of motion and mean angular velocity showed weak correlations with disability (r = −0.25 and −0.30, respectively; p < 0.05) and weak-to-moderate correlations with kinesiophobia (r = −0.30 and −0.40, respectively; p < 0.05). No significant correlation was observed between headache features and total cervical range of motion or mean angular velocity (p > 0.05). No differences in the percentage of activation of both flexors and extensors cervical muscles during active neck movements were seen (p > 0.05). In conclusion, episodic and chronic migraines were associated with less mobility and less velocity of neck movements, without differences within muscle activity. Neck disability and kinesiophobia are negative and weakly associated with cervical movement.

Comparison of cervical muscle isometric force between migraine subgroups or migraine-associated neck pain: a controlled study

This study aimed to verify if migraine frequency or migraine-associated neck pain were associated with a reduction of normalized force and altered electromyographic activity during maximal cervical muscle isometric contractions. Additionally, it aimed to assess the correlation of normalized isometric force with years with migraine, headache frequency, headache intensity, migraine-related disability, and severity of cutaneous allodynia. The sample comprises 71 women with migraine (40/31 episodic/chronic, 42/18 with/without neck pain) and 32 women without headache. Cervical muscle isometric force in flexion, extension, and lateral flexion was assessed synchronized with the acquisition of superficial electromyography from the cervical muscles. Women with episodic migraine presented lower normalized isometric force in extension, flexion, and right and left lateral flexions than controls (P < 0.05). Women with migraine and neck pain exhibited lower cervical extension and right/left lateral-flexions normalized isometric force than controls (P < 0.05). No significant differences were observed in antagonist activity. Normalized isometric force in all directions showed weak to moderate correlations with the severity of self-reported symptoms of cutaneous allodynia (- 0.25 ≥ r ≥ - 0.39). No additional linear correlation with clinical migraine features was observed. In conclusion, cervical muscle weakness may be associated with episodic migraine and neck pain concurrent with migraine attacks without altered antagonist activity. Additionally, it may also be related to the severity of cutaneous allodynia.

Comprehensive management of adults with chronic migraine: Clinical practice guidelines in Mexico

Introduction:

Migraine is a polygenic multifactorial disorder with a neuronal initiation of a cascade of neurochemical processes leading to incapacitating headaches. Headaches are generally unilateral, throbbing, 4–72 h in duration, and associated with nausea, vomiting, photophobia, and sonophobia. Chronic migraine (CM) is the presence of a headache at least 15 days per month for ≥3 months and has a high global impact on health and economy, and therapeutic guidelines are lacking.

Methods:

Using the Grading of Recommendations, Assessment, Development, and Evaluations system, we conducted a search in MEDLINE and Cochrane to investigate the current evidence and generate recommendations of clinical practice on the identification of risk factors and treatment of CM in adults.

Results:

We recommend avoiding overmedication of non-steroidal anti-inflammatory drugs (NSAIDs); ergotamine; caffeine; opioids; barbiturates; and initiating individualized prophylactic treatment with topiramate eptinezumab, galcanezumab, erenumab, fremanezumab, or botulinum toxin. We highlight the necessity of managing comorbidities initially. In the acute management, we recommend NSAIDs, triptans, lasmiditan, and gepants alone or with metoclopramide if nausea or vomiting. Non-pharmacological measures include neurostimulation.

Conclusions:

We have identified the risk factors and treatments available for the management of CM based on a grading system, which facilitates selection for individualized management.

A narrative review of the importance of pharmacokinetics and drug-drug interactions of preventive therapies in migraine management

Objective

To review the pharmacokinetics of major classes of migraine preventives and the clinical implications of drug–drug interactions (DDIs) with the use of these therapies in migraine management.

Background

Preventive treatments for migraine are recommended for a large proportion of patients with frequent migraine attacks. These patients often exhibit a number of comorbidities, which may lead to the introduction of multiple concomitant therapies. Potential DDIs must be considered when using polytherapy to avoid increased risk of adverse events (AEs) or inadequate treatment of comorbid conditions.

Methods

A literature search was performed to identify pharmacokinetic properties and potential DDIs of beta‐blockers, antiepileptic drugs, antidepressants, calcium channel blockers, gepants, and monoclonal antibody therapies targeting the calcitonin gene‐related peptide pathway with medications that may be used for comorbid conditions.

Results

Most DDIs occur through alterations in cytochrome P450 isoenzyme activity and may be complicated by genetic polymorphism for metabolic enzymes. Additionally, drug metabolism may be altered by grapefruit juice ingestion and smoking. The use of migraine preventive therapies may exacerbate symptoms of comorbid conditions or increase the risk of AEs associated with comorbid conditions as a result of DDIs.

Conclusions

DDIs are important to consider in patients with migraine who use multiple medications. The development of migraine‐specific evidence‐based preventive treatments allows for tailored clinical management that reduces the risk of DDIs and associated AEs in patients with comorbidities.

Characterization of chronic overlapping pain conditions in patients with chronic migraine: A CHOIR study

OBJECTIVE

Chronic overlapping pain conditions (COPCs) represent a co-aggregation of widespread pain disorders. We characterized differences in physical and psychosocial functioning in patients with chronic migraine (CM) and those with CM and COPCs.

BACKGROUND

Patients with CM and COPCs have been identified as a distinct subgroup of patients with CM, and these patients may be vulnerable to greater symptom severity and burden.

METHODS

Data were extracted from Collaborative Health Outcomes Information Registry (an open-source learning health-care system), completed at the patients' first visit at a large tertiary care pain management center and electronic medical records. In 1601 patients with CM, the number of non-cephalic areas of pain endorsed on a body map was used to examine the differences in pain, physical and psychosocial function, adverse life experience, and health-care utilization.

RESULTS

Patients endorsing more body map regions reported significantly worse symptoms and function across all domains. Scored on a t-score metric (mean = 50, SD = 10), endorsement of one additional body map region corresponded with a 0.69-point increase in pain interference (95% CI = 0.55, 0.82; p < 0.001; Cohen's f = 0.328), 1.15-point increase in fatigue (95% CI = 0.97, 1.32; p < 0.001; Cohen's f = 0.432), and 1.21-point decrease in physical function (95% CI = -1.39, -1.03; p < 0.001; Cohen's f = 0.560). Patients with more widespread pain reported approximately 5% more physician visits (95% CI = 0.03, 0.07; p < 0.001), and patients reporting adverse life events prior to age 17 endorsed 22% more body map regions (95% CI = 0.11, 0.32; p < 0.001).

CONCLUSIONS

Patients with CM and other overlapping pain conditions as noted on the body map report significantly worse pain-related physical function, psychosocial functioning, increased health-care utilization, and greater association with adverse life experiences, compared with those with localized CM. This study provides further evidence that patients with CM and co-occurring pain conditions are a distinct subgroup of CM and can be easily identified through patient-reported outcome measures.

Female Gender Is Associated with a Higher Prevalence of Chronic Neck Pain, Chronic Low Back Pain, and Migraine: Results of the Spanish National Health Survey, 2017

OBJECTIVES

To assess the prevalence of chronic neck pain (CNP), chronic low back pain (CLBP), and migraine headache (MH) in the Spanish population and to identify sociodemographic and health-related variables associated with CNP, CLBP, and MH.

DESIGN

Observational study.

SETTING

Spain.

SUBJECTS

A total of 22,511 persons 18 years of age or older (10,304 males and 12,207 females) who participated in the 2017 Spanish National Health Survey.

METHODS

Stratified three-stage sampling was applied. CNP, CLBP, and MH were the dependent variables. The analysis was conducted separately by gender. Sociodemographic features, self-perceived health status, lifestyle habits, comorbidities, and pain features were analyzed by using logistic regression models.

RESULTS

Females reported a higher prevalence of CNP, CLBP, and MH (P < 0.001) than males. For both sexes, anxiety and/or depression and poor self-rated health were associated with a significantly increased prevalence of CNP, CLBP, and MH. For CNP and CLBP, the identified associated factors were older age and limitations to usual activity. For CNP and MH, the most common associated factor was comorbid respiratory disease.

CONCLUSIONS

Our study identified several factors associated with CNP, CLBP, and MH in Spanish female and male adults, with potential implications for health care providers.

Gray Matter Structural Alterations in Chronic and Episodic Migraine: A Morphometric Magnetic Resonance Imaging Study

OBJECTIVE

This study evaluates different parameters describing the gray matter structure to analyze differences between healthy controls, patients with episodic migraine, and patients with chronic migraine.

DESIGN

Cohort study.

SETTING

Spanish community.

SUBJECTS

Fifty-two healthy controls, 57 episodic migraine patients, and 57 chronic migraine patients were included in the study and underwent T1-weighted magnetic resonance imaging acquisition.

METHODS

Eighty-four cortical and subcortical gray matter regions were extracted, and gray matter volume, cortical curvature, thickness, and surface area values were computed (where applicable). Correlation analysis between clinical features and structural parameters was performed.

RESULTS

Statistically significant differences were found between all three groups, generally consisting of increases in cortical curvature and decreases in gray matter volume, cortical thickness, and surface area in migraineurs with respect to healthy controls. Furthermore, differences were also found between chronic and episodic migraine. Significant correlations were found between duration of migraine history and several structural parameters.

CONCLUSIONS

Migraine is associated with structural alterations in widespread gray matter regions of the brain. Moreover, the results suggest that the pattern of differences between healthy controls and episodic migraine patients is qualitatively different from that occurring between episodic and chronic migraine patients.

Repetitive stress in mice causes migraine-like behaviors and calcitonin gene-related peptide-dependent hyperalgesic priming to a migraine trigger

Migraine is one of the most disabling disorders worldwide but the underlying mechanisms are poorly understood. Stress is consistently reported as a common trigger of migraine attacks. Here, we show that repeated stress in mice causes migraine-like behaviors that are responsive to a migraine therapeutic. Adult female and male mice were exposed to 2 hours of restraint stress for 3 consecutive days, after which they demonstrated facial mechanical hypersensitivity and facial grimace responses that were resolved by 14 days after stress. Hypersensitivity or grimace was not observed in either control animals or those stressed for only 1 day. After return to baseline, the nitric oxide donor sodium nitroprusside (SNP; 0.1 mg/kg) elicited mechanical hypersensitivity in stressed but not in control animals, demonstrating the presence of hyperalgesic priming. This suggests the presence of a migraine-like state, because nitric oxide donors are reliable triggers of attacks in migraine patients but not controls. The stress paradigm also caused priming responses to dural pH 7.0 treatment. The presence of this primed state after stress is not permanent because it was no longer present at 35 days after stress. Finally, mice received either the calcitonin gene-related peptide monoclonal antibody ALD405 (10 mg/kg) 24 hours before SNP or a coinjection of sumatriptan (0.6 mg/kg). ALD405, but not sumatriptan, blocked the facial hypersensitivity due to SNP. This stress paradigm in mice and the subsequent primed state caused by stress allow further preclinical investigation of mechanisms contributing to migraine, particularly those caused by common triggers of attacks.

Muscle endurance and cervical electromyographic activity during submaximal efforts in women with and without migraine

BACKGROUND

Despite previous reports supporting cervical muscle weakness and altered motor control in migraine, the endurance under standardized submaximal loads has not been investigated. Therefore, this study aimed to assess the endurance and muscle activity of the cervical musculature during submaximal isometric contractions in women with migraine and those without headache.

METHODS

Cervical muscle endurance tests were performed for flexors and extensors at 25%, 50%, and 75% of the output force during maximal isometric contraction using the Multi-Cervical Rehabilitation Unit with customized biofeedback. Initial values and relative rates of changes in root mean square and median frequency were calculated using cervical muscle superficial electromyography.

FINDINGS

Women with chronic migraine presented significantly shorter flexor endurance time in all load tests than controls (25%, P = .001, 50%, P = .005; 75%, P = .013), while episodic migraine only differed from controls at 75% (P = .018). The frequency of neck pain and/or pain referred to the head after the endurance test was up 12% in the control group, 40% in the episodic migraine group and 68% of the chronic migraine group. Few differences between groups were observed in the electromyographic variables and none of them was related to a worse performance in the endurance tests.

INTERPRETATION

Cervical flexor endurance was reduced in women with chronic migraine when independent of the load, whereas it was reduced to 75% of the maximal force in those with episodic migraine. No difference in the electromyographic variables could be related to this reduced flexor endurance. Also, no differences were detected in extensors endurance.

Are Migraine Patients at Increased Risk for Symptomatic Coronavirus Disease 2019 Due to Shared Comorbidities?

The coronavirus disease 2019 (COVID-19) pandemic has rapidly transformed the whole world and forced us to look through comorbid diseases and risk factors from a different perspective. COVID-19 shows some inherent risk factors like cardiovascular comorbidities independent from age, gender, and geographic location. One of the most peculiar features of the COVID-19 pandemic is that severe acute respiratory syndrome coronavirus 2 respiratory infections disproportionately impact patients with hypertension, diabetes, and other cardiovascular comorbidities rather than those with allergic respiratory diseases and immune-compromised conditions. Migraine is a complex neuro-vasculo-inflammatory disorder that is also packed frequently with certain medical conditions including vascular disorders, hypertension, allergic diseases such as asthma and systemic inflammatory disorders. Accordingly, 2 different questions arise during the pandemic: (1) Do share comorbidities of cardiovascular diseases and hypertension increase the risk of symptomatic COVID-19 for migraine patients? (2) Do comorbid allergic and atopic diseases, including asthma act as opposite influencers alongside with female gender? This paper focuses on the co-existence of comorbidities of COVID-19, in comparison with migraine, based on a wide clinical dataset and available reports. Discussed mechanisms include potential strategic roles of angiotensin-converting enzyme 2, angiotensin-II, and nucleotide oligomerization domain-like receptor family, pyrin domain containing 3 inflammasome, playing remarkable parts in the pathogenesis of COVID-19 and migraine. There are also some clues about the importance of endothelial and pericyte dysfunction and neuroinflammation in COVID-19 infection, related to complications and survival of the patients. The large epidemiological studies as well as basic research, focusing on migraine patients with COVID-19 will clarify these vital questions during the upcoming periods.

Optogenetic Spreading Depression Elicits Trigeminal Pain and Anxiety Behavior

OBJECTIVE

Cortical spreading depression (SD) is an intense depolarization underlying migraine aura. Despite the weight of evidence linking SD to the pain phase of migraine, controversy remains over a causal role of SD in cephalgia because of the invasive nature of previous SD induction methods. To overcome this problem, we used a novel minimally invasive optogenetic SD induction method and examined the effect of SD on behavior.

METHODS

Optogenetic SD was induced as a single event or repeatedly every other day for 2 weeks. End points, including periorbital and hindpaw mechanical allodynia, mouse grimace, anxiety, and working memory, were examined in male and female mice.

RESULTS

A single SD produced bilateral periorbital mechanical allodynia that developed within 1 hour and resolved within 2 days. Sumatriptan prevented periorbital allodynia when administered immediately after SD. Repeated SDs also produced bilateral periorbital allodynia that lasted 4 days and resolved within 2 weeks after the last SD. In contrast, the hindpaw withdrawal thresholds did not change after repeated SDs suggesting that SD-induced allodynia was limited to the trigeminal region. Moreover, repeated SDs increased mouse grimace scores 2 days after the last SD, whereas a single SD did not. Repeated SDs also increased thigmotaxis scores as a measure of anxiety. In contrast, neither single nor repeated SDs affected visuospatial working memory. We did not detect sexual dimorphism in any end point.

INTERPRETATION

Altogether, these data show a clinically congruent causal relationship among SD, trigeminal pain, and anxiety behavior, possibly reflecting SD modulation of hypothalamic, thalamic, and limbic mechanisms. ANN NEUROL 2021;89:99-110.

What is changing in chronic migraine treatment? An algorithm for onabotulinumtoxinA treatment by the Italian chronic migraine group

INTRODUCTION

OnabotulinumtoxinA (OBT-A) and monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway are two of the few treatments that ameliorate chronic migraine (CM) in randomized controlled trials and real-life studies. Separate clinical practice guidelines have been developed for the management of CM with OBT-A or CGRP-targeting mAbs.

AREAS COVERED

Considering the concomitant availability of OBT-A and CGRP-targeting mAbs as therapeutic treatment options, Italian migraine experts reviewed the evidence supporting the efficacy of OBT-A and CGRP-targeting mAbs in CM in order to rationalize the management of CM patients treated with OBT-A. Experts addressed everyday practice needs to shape the optimal pharmacological management by balancing adherence to regulatory indications, ethical considerations, and clinical expertise. Considering the remarkable challenge of improving the health and quality of life of patients with CM, even partial improvements may be clinically meaningful, particularly for those who are resistant or intolerant to oral migraine treatments.

EXPERT OPINION

In this collaborative effort, we propose a treatment algorithm that integrates the relevant aspects of managing patients with CM to provide ready-to-use practical guidance regarding the appropriate use of OBT-A.

Evaluation of green light exposure on headache frequency and quality of life in migraine patients: A preliminary one-way cross-over clinical trial

BACKGROUND

Pharmacological management of migraine can be ineffective for some patients. We previously demonstrated that exposure to green light resulted in antinociception and reversal of thermal and mechanical hypersensitivity in rodent pain models. Given the safety of green light emitting diodes, we evaluated green light as a potential therapy in patients with episodic or chronic migraine.

MATERIAL AND METHODS

We recruited (29 total) patients, of whom seven had episodic migraine and 22 had chronic migraine. We used a one-way cross-over design consisting of exposure for 1-2 hours daily to white light emitting diodes for 10 weeks, followed by a 2-week washout period followed by exposure for 1-2 hours daily to green light emitting diodes for 10 weeks. Patients were allowed to continue current therapies and to initiate new treatments as directed by their physicians. Outcomes consisted of patient-reported surveys. The primary outcome measure was the number of headache days per month. Secondary outcome measures included patient-reported changes in the intensity and frequency of the headaches over a two-week period and other quality of life measures including ability to fall and stay asleep, and ability to perform work. Changes in pain medications were obtained to assess potential reduction.

RESULTS

When seven episodic migraine and 22 chronic migraine patients were analyzed as separate cohorts, white light emitting diodes produced no significant change in headache days in either episodic migraine or chronic migraine patients. Combining data from the episodic migraine and chronic migraine groups showed that white light emitting diodes produced a small, but statistically significant reduction in headache days from (days ± SEM) 18.2 ± 1.8 to 16.5 ± 2.01 days. Green light emitting diodes resulted in a significant decrease in headache days from 7.9 ± 1.6 to 2.4 ± 1.1 and from 22.3 ± 1.2 to 9.4 ± 1.6 in episodic migraine and chronic migraine patients, respectively. While some improvement in secondary outcomes was observed with white light emitting diodes, more secondary outcomes with significantly greater magnitude including assessments of quality of life, Short-Form McGill Pain Questionnaire, Headache Impact Test-6, and Five-level version of the EuroQol five-dimensional survey without reported side effects were observed with green light emitting diodes. Conclusions regarding pain medications reduction with green light emitting diode exposure were not possible. No side effects of light therapy were reported. None of the patients in the study reported initiation of new therapies.

DISCUSSION

Green light emitting diodes significantly reduced the number of headache days in people with episodic migraine or chronic migraine. Additionally, green light emitting diodes significantly improved multiple secondary outcome measures including quality of life and intensity and duration of the headache attacks. As no adverse events were reported, green light emitting diodes may provide a treatment option for those patients who prefer non-pharmacological therapies or may be considered in complementing other treatment strategies. Limitations of this study are the small number of patients evaluated. The positive data obtained support implementation of larger clinical trials to determine possible effects of green light emitting diode therapy.This study is registered with clinicaltrials.gov under NCT03677206.

Comorbid and co-occurring conditions in migraine and associated risk of increasing headache pain intensity and headache frequency: results of the migraine in America symptoms and treatment (MAST) study

Background

Migraine has many presumed comorbidities which have rarely been compared between samples with and without migraine. Examining the association between headache pain intensity and monthly headache day (MHD) frequency with migraine comorbidities is novel and adds to our understanding of migraine comorbidity.

Methods

The MAST Study is a prospective, web-based survey that identified US population samples of persons with migraine (using modified International Classification of Headache Disorders-3 beta criteria) and without migraine. Eligible migraine participants averaged ≥1 MHDs over the prior 3 months. Comorbidities “confirmed by a healthcare professional diagnosis” were endorsed by respondents from a list of 21 common cardiovascular, neurologic, psychiatric, sleep, respiratory, dermatologic, pain and medical comorbidities. Multivariable binary logistic regression calculated odds ratios (OR) and 95% confidence intervals for each condition between the two groups adjusting for sociodemographics. Modeling within the migraine cohort assessed rates of conditions as a function of headache pain intensity, MHD frequency, and their combination.

Results

Analyses included 15,133 people with migraine (73.0% women, 77.7% White, mean age 43 years) and 77,453 controls (46.4% women, 76.8% White, mean age 52 years). People with migraine were significantly (P < 0.001) more likely to report insomnia (OR 3.79 [3.6, 4.0]), depression (OR 3.18 [3.0, 3.3]), anxiety (OR 3.18 [3.0 3.3]), gastric ulcers/GI bleeding (OR 3.11 [2.8, 3.5]), angina (OR 2.64 [2.4, 3.0]) and epilepsy (OR 2.33 [2.0, 2.8]), among other conditions. Increasing headache pain intensity was associated with comorbidities related to inflammation (psoriasis, allergy), psychiatric disorders (depression, anxiety) and sleep conditions (insomnia). Increasing MHD frequency was associated with increased risk for nearly all conditions and most prominent among those with comorbid gastric ulcers/GI bleeding, diabetes, anxiety, depression, insomnia, asthma and allergies/hay fever.

Conclusions

In regression models controlled for sociodemographic variables, all conditions studied were reported more often by those with migraine. Whether entered into the models separately or together, headache pain intensity and MHD frequency were associated with increased risk for many conditions. Future work is required to understand the causal sequence of relationships (direct causality, reverse causality, shared underlying predisposition), the potential confounding role of healthcare professional consultation and treatment, and potential detection bias.

Advance in genetics of migraine

Purpose of review

Migraine is a primary headache disorder and one of the most common and disabling neurological diseases worldwide. Genome-wide association studies have identified ≈40 genetic loci associated with migraine. How these and other genetic findings are used to expand our knowledge on the pathophysiological mechanism of common migraine and rare migraine variants will be discussed.

Recent findings

The genetic load, based on common polygenic variation, is higher in familial migraine cases than in nonfamilial cases, and higher for migraine with aura and hemiplegic migraine. Migraine shares common genetic variant risks with depression. Specific clinical features of common migraine seem to be determined by genetic factors. A stronger family history of migraine is associated with lower age-at-onset, higher frequency and number of medication days and the migraine with aura subtype. Mild hemiplegic migraine is likely caused by complex polygenic interaction of multiple gene variants and environmental factors, like in common migraine subtypes. Phenotypical features in hemiplegic migraine patients may guide physicians in providing adequate genetic counseling.

Summary

Integration of genetic, phenotypic and epigenetic data will help to identify the biological mechanisms by which genetic factors contribute to migraine pathogenesis. Recent studies show the impact of genetics on clinical features and comorbidities in migraine and may guide clinicians to an adequate genetic advice for patients.

Exploring Natural Clusters of Chronic Migraine Phenotypes: A Cross-Sectional Clinical Study

Heterogeneity in chronic migraine (CM) presents significant challenge for diagnosis, management, and clinical trials. To explore naturally occurring clusters of CM, we utilized data reduction methods on migraine-related clinical dataset. Hierarchical agglomerative clustering and principal component analyses (PCA) were conducted to identify natural clusters in 100 CM patients using 14 migraine-related clinical variables. Three major clusters were identified. Cluster I (29 patients) - the severely impacted patient featured highest levels of depression and migraine-related disability. Cluster II (28 patients) - the minimally impacted patient exhibited highest levels of self-efficacy and exercise. Cluster III (43 patients) - the moderately impacted patient showed features ranging between Cluster I and II. The first 5 principal components (PC) of the PCA explained 65% of variability. The first PC (eigenvalue 4.2) showed one major pattern of clinical features positively loaded by migraine-related disability, depression, poor sleep quality, somatic symptoms, post-traumatic stress disorder, being overweight and negatively loaded by pain self-efficacy and exercise levels. CM patients can be classified into three naturally-occurring clusters. Patients with high self-efficacy and exercise levels had lower migraine-related disability, depression, sleep quality, and somatic symptoms. These results may ultimately inform different management strategies.

Migraine pathways and the identification of novel therapeutic targets

Introduction: Migraine is a chronic neurovascular disorder characterized by recurrent headache attacks associated with neurological and autonomic symptoms. The pathophysiological mechanisms of the disease are extremely complex, involving hypothalamic and trigeminovascular activation, cortical spreading depression, release of pro-inflammatory peptides, peripheral and central sensitization. The underlying cellular and molecular mechanisms have been scarcely investigated. Recently, genetic studies have suggested that different metabolic pathways could be involved in the pathogenesis of migraine.Areas covered: This review focuses on cellular and molecular mechanisms involved in migraine, suggesting a role for circadian clocks, ion channels, synaptic plasticity, vascular factors, ion metal homeostasis, and impaired glucose metabolism in the pathogenesis of the disease. Accordingly, the article proposes new therapeutic targets that may be of particular relevance for disease prevention.Expert opinion: Several complex molecular mechanisms are involved in setting the genetic threshold for migraine and the pathogenesis of headache attacks. Most promising new therapeutic targets are the modulation of hypothalamic activity and ion channels involved in pain transmission. Further studies in animals and humans are necessary to enhance the elucidation of the molecular mechanisms of migraine and open new avenues for disease prevention.

White matter changes in chronic and episodic migraine: a diffusion tensor imaging study

BACKGROUND

White matter alterations have been observed in patients with migraine. However, no microstructural white matter alterations have been found particularly in episodic or chronic migraine patients, and there is limited research focused on the comparison between these two groups of migraine patients.

METHODS

Fifty-one healthy controls, 55 episodic migraine patients and 57 chronic migraine patients were recruited and underwent brain T1-weighted and diffusion-weighted MRI acquisition. Using Tract-Based Spatial Statistics (TBSS), fractional anisotropy, mean diffusivity, radial diffusivity and axial diffusivity were compared between the different groups. On the one hand, all migraine patients were compared against healthy controls. On the other hand, patients from each migraine group were compared between them and also against healthy controls. Correlation analysis between clinical features (duration of migraine in years, time from onset of chronic migraine in months, where applicable, and headache and migraine frequency, where applicable) and Diffusion Tensor Imaging measures was performed.

RESULTS

Fifty healthy controls, 54 episodic migraine and 56 chronic migraine patients were finally included in the analysis. Significant decreased axial diffusivity (p < .05 false discovery rate and by number of contrasts corrected) was found in chronic migraine compared to episodic migraine in 38 white matter regions from the Johns Hopkins University ICBM-DTI-81 White-Matter Atlas. Significant positive correlation was found between time from onset of chronic migraine and mean fractional anisotropy in the bilateral external capsule, and negative correlation between time from onset of chronic migraine and mean radial diffusivity in the bilateral external capsule.

CONCLUSIONS

These findings suggest global white matter structural differences between episodic migraine and chronic migraine. Patients with chronic migraine could present axonal integrity impairment in the first months of chronic migraine with respect to episodic migraine patients. White matter changes after the onset of chronic migraine might reflect a set of maladaptive plastic changes.

Pharmaceutically treated comorbidities and associated healthcare costs among triptan users in Switzerland: A pharmacoepidemiological study from a nationwide health insurance database

PURPOSE

In course of the new migraine drug development on the global market it is important to quantify the current burden of migraine medication. This study aimed to estimate the comorbidity burden and its relation to healthcare costs in patients using triptans in Switzerland by analyzing a large population-based database.

METHODS

This retrospective cohort study was based on Swiss health insurance claims data (2015/2016). The study sample comprised adult patients with ≥1 triptan prescription in 2015. We evaluated pharmaceutically treated comorbid conditions (CCs) and costs (12 months after index prescription) of patients using triptan. Multivariable linear regression models with log-transformed outcomes were performed to identify the factors related to healthcare costs.

RESULTS

From a total of 749 092, we identified 10,090 patients using triptans (1-year prevalence of 1.35%), whereas 58.9% had ≥2 CCs. The most frequent CCs were pain- and rheumatologic-related diseases and psychological disorders. Among triptan users, the mean total healthcare costs were highest in older patients with ≥2 CCs (>64 years: migraine with ≥2 CC "12 331 SFr"). Multivariate regression analyses showed that psychological disorders had the strongest impact on healthcare costs (Coefficient: 1.29; 95%-CI: 1.27-1.31).

CONCLUSIONS

The present study provides an overview of comorbidities and its related costs in migraine patients, which helps to quantify the current burden of migraine. This is relevant as the recently licensed CGRP antagonists are likely to change current treatment schemes for migraine, which strongly depends also on the comorbidities. The present study might therefore be helpful for the future development of treatment guidelines.

Migraine progression in subgroups of migraine based on comorbidities: Results of the CaMEO Study

Objective

To test the hypothesis that statistically defined subgroups of migraine (based on constellations of comorbidities and concomitant conditions; henceforth comorbidities), previously identified using Chronic Migraine Epidemiology and Outcomes (CaMEO) Study data, differ in prognosis, as measured by rates of progression from episodic migraine (EM) to chronic migraine (CM).

Methods

The onset of CM was assessed up to 4 times over 12 months in individuals with EM and ≥1 comorbidity at baseline, based on constellations of comorbidities (comorbidity classes). The “fewest comorbidities” class served as reference. Individuals completing ≥1 follow-up survey from the web-based CaMEO Study were included. Covariates included sociodemographic variables and headache characteristics. Sex, income, cutaneous allodynia, and medication overuse were modeled as binary variables; age, body mass index, headache-related disability (Migraine Disability Assessment [MIDAS]), and Migraine Symptom Severity Scale as continuous variables. CM onset was assessed using discrete time analysis.

Results

In the final sociodemographic model, all comorbidity classes had significantly elevated hazard ratios (HRs) for risk of progression to CM from EM, relative to fewest comorbidities. HRs for CM onset ranged from 5.34 (95% confidence interval [CI] 3.89–7.33; p ≤ 0.001) for most comorbidities to 1.53 (95% CI 1.17–2.01; p < 0.05) for the respiratory class. After adjusting for headache covariates independently, each comorbidity class significantly predicted CM onset, although HRs were attenuated.

Conclusions

Subgroups of migraine identified by comorbidity classes at cross-section predicted progression from EM (with ≥1 comorbidity at baseline) to CM. The relationship of comorbidity group to CM onset remained after adjusting for indicators of migraine severity, such as MIDAS.

Clinicaltrials.gov identifier

NCT01648530.