Familial occurrence of migraine with aura in a population-based study

Aeromedical Risk of Migraine

INTRODUCTION: Migraine is a common condition that can carry considerable risk to aeromedical duties. Because randomized controlled trials are not an appropriate method to evaluate flight safety risk for medical conditions that may cause subtle or sudden incapacitation, the determination of fitness-to-fly must be based on risk assessments informed by extrapolated evidence. Therefore, we conducted a review of current literature to provide background information to inform the aeromedical risk assessment of migraine using a risk matrix approach.METHODS: We identified studies on topics pertinent to conducting an aeromedical risk assessment of migraine. We generated an overview of the literature synthesizing the findings of articles retrieved from searches of Scopus, Ovid, PubMed, and the Cochrane Library published in English from all years, in both general and aircrew populations. International headache and neurology guidelines, as well as headache policies from the U.S. Air Force, were also reviewed.RESULTS: This review includes information on the following topics relevant to conducting an evidence-based risk assessment of migraine: diagnosis, prevalence, incidence, natural course, clinical presentation, triggers, comorbidities, neuroimaging, implications of family history, and efficacy of pharmacological and nonpharmacological therapies.DISCUSSION: This review summarizes current literature on migraine for use in a risk matrix approach to the aeromedical assessment of migraine in prospective and current aircrew. Awareness of the most current epidemiological data related to a variety of migraine parameters facilitates an evidence-based risk assessment of migraine in aircrew and requires iterative updates as new information becomes available.Mainland RL, Skinner CR, Saary J. Aeromedical risk of migraine. Aerosp Med Hum Perform. 2024; 95(2):101-112.

Sex Differences in Chronic Migraine: Focusing on Clinical Features, Pathophysiology, and Treatments

PURPOSE OF REVIEW

This review provides an update on sex differences in chronic migraine (CM), with a focus on clinical characteristics, pathophysiology, and treatments.

RECENT FINDINGS

Approximately 6.8-7.8% of all migraineurs have CM, with an estimated prevalence of 1.4-2.2% in the general population. The economic burden caused by CM, including medical costs and lost working ability, is threefold higher than that caused by episodic migraine (EM). Notably, the prevalence of migraine is affected by age and sex. Female migraineurs with CM experience higher levels of headache-related disability, including longer headache duration, higher frequency of attacks, and more severely impacted efficiency at work. Sex hormones, including estrogen, testosterone, and progesterone, contribute to the sexually dimorphic characteristics and prevalence of migraine in men and women. Recent neuroimaging studies have indicated that migraine may have a greater impact and cause greater dysfunction in the organization of resting-state functional networks in women. Accumulating evidence suggests that topiramate, Onabotulinumtoxin A and calcitonin gene-related peptide (CGRP) monoclonal antibodies are effective as the preventative treatments for CM. Recent evidence highlights a divergence in the characteristics of CM between male and female populations. The data comparing the treatment response for CM regarding sex are lacking.

Associations between migraine occurrence and the effect of aura, age at onset, family history, and sex: A cross-sectional study

Introduction

The relationships between family history, sex, age at onset, and migraine occurrence have been documented. However, the associations between these factors across different sexes and subgroups of patients have yet to be elucidated. This study evaluated the association between family history and migraine in male and female patients experiencing episodic and chronic migraine with and without aura.

Methods

This cross-sectional, case–control study included 299 headache-free controls and 885 patients receiving outpatient treatment for migraine. Participants were classified into episodic (1–14 days/month) and chronic (≥15 days/month) migraine groups.

Results

Positive family history was significantly more frequently observed in the episodic group than in the chronic group (49.5% vs. 26%; P < 0.001) in male patients, particularly in male patients without aura (50.3% vs. 21.9%; P = 0.003); it was less frequently observed (58.7% vs. 73.7%; P = 0.048) in female patients with aura. Family history was correlated with an earlier age at onset (20.7 years vs. 22.8 years; P = 0.002), particularly in patients without aura (21 years vs. 23.7 years; P = 0.002), who were women (20.9 years vs. 23.9 years; P = 0.002).

Conclusions

Different patterns of association between family history and migraine can be observed between men and women. A positive family history of migraine is correlated with an earlier age at onset, particularly among female patients without aura.

Linking migraine frequency with family history of migraine

Background

Migraine is a complex genetic disorder that is brought about by multiple genetic and environmental factors. We aimed to assess whether migraine frequency is associated with genetic susceptibility.

Methods

We investigated in 2829 migraine patients (14% males) whether ‘migraine frequency’ (measured as the number of migraine days per month) was related to ‘genetic load’ (measured as the number of parents affected with migraine) using a validated web-based questionnaire. In addition, we investigated associations with age-at-onset, migraine subtype, use of acute headache medication, and comorbid depression.

Results

We found an association between the number of migraine days per month and family history of migraine for males (p = 0.03), but not for females (p = 0.97). This association was confirmed in a linear regression analysis. Also, a lower age-at-onset (p < 0.001), having migraine with aura (p = 0.03), and a high number of medication days (p = 0.006) were associated with a stronger family history of migraine, whereas lifetime depression (p = 0.13) was not.

Discussion

Migraine frequency, as measured by the number of migraine days per month, seems associated with a genetic predisposition only in males. A stronger family history of migraine was also associated with a lower age-at-onset, a higher number of medication days, and migraine with aura. Our findings suggest that specific clinical features of migraine seem more determined by genetic factors.

Familial occurrence of headache disorders: A population-based study in mainland China

BACKGROUND

Headache disorders are highly prevalent worldwide, and familial occurrence and heredity are contributory factors attracting the interest of epidemiological researchers. Our purpose, in a large sample drawn nationwide from the Chinese general population, was to evaluate the frequency of similar headache in first-degree relatives (FDRs) of those with different headache types.

METHODS

This was a questionnaire-based nationwide cross-sectional door-to-door survey using cluster random-sampling, selecting one adult (18-65 years) per household. Headache was diagnosed by ICHD-II criteria. Participants with headache were asked whether or not any FDRs had similar headache to their own. Chi-squared test and multivariate logistic regression analysis were used to assess the strength and significance of associations.

RESULTS

Of 5041 survey participants (participation rate 94.1%), 1060 (21.0%) were diagnosed with headache (migraine 469 [9.3%], tension-type headache [TTH] 543 [10.8%], headache on ≥15 days/month 48 [0.95%]). From these, 31 were excluded because of missing data about FDRs, leaving 1029 for analysis (male 350 [mean age: 46.7±11.4years]; female 679 [mean age 46.3±11.2years]). Similar headache in one or more FDRs was reported by 22.2% (95% CI: 19.6-24.7%) overall, by 25.1% (21.1-29.1%) of those with migraine, by 19.1% (15.7-22.4%) with TTH and by 29.2% (16.3-42.0%) with headache on ≥15 days/month. The differences was significant between migraine and TTH (OR=1.4, p=0.023), but were not significant between headache on ≥15 days/month and TTH (OR=1.7, p=0.093), migraine and headache on ≥15 days/month (OR=1.2,p=0.534). In multivariate analysis: for migraine versus TTH,AOR=1.2 (p=0.015); for headache on ≥15 days/month versus TTH, AOR 2.3 (p=0.018).

CONCLUSION

Headache was highly prevalent in China and common among FDRs of those with any type of headache (headache on ≥15 days/month>migraine>TTH). Against the background of the general-population prevalence of each disorder, familial occurrence was a very highly influential factor in headache on ≥15 days/month. There are important implications in this for public health and education.

Sex Differences in the Transmission of Migraine

Consistent evidence demonstrates that migraine is far more common in women than in men, but the explanations for this preponderance have not been systematically evaluated. We examined whether the female preponderance is attributable to genetic factors using data from a controlled family study which included 260 probands and their 1232 first-degree adult relatives. We found that although the risk of migraine was three times greater among the relatives of probands with migraine compared with controls, there was no differential risk of migraine among the relatives of male vs. female probands with migraine. Taking these data together with other family studies, we conclude that the increased risk of migraine in females is likely to result from increased exposure to non-familial endogenous or exogenous risk factors for migraine that lower the threshold for expression of migraine in women.

Familial Aggregation of Migraine and Depression: Insights From a Large Australian Twin Sample

OBJECTIVES

This research examined the familial aggregation of migraine, depression, and their co-occurrence.

METHODS

Diagnoses of migraine and depression were determined in a sample of 5,319 Australian twins. Migraine was diagnosed by either self-report, the ID migraine™ Screener, or International Headache Society (IHS) criteria. Depression was defined by fulfilling either major depressive disorder (MDD) or minor depressive disorder (MiDD) based on the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria. The relative risks (RR) for migraine and depression were estimated in co-twins of twin probands reporting migraine or depression to evaluate their familial aggregation and co-occurrence.

RESULTS

An increased RR of both migraine and depression in co-twins of probands with the same trait was observed, with significantly higher estimates within monozygotic (MZ) twin pairs compared to dizygotic (DZ) twin pairs. For cross-trait analysis, the RR for migraine in co-twins of probands reporting depression was 1.36 (95% CI: 1.24-1.48) in MZ pairs and 1.04 (95% CI: 0.95-1.14) in DZ pairs; and the RR for depression in co-twins of probands reporting migraine was 1.26 (95% CI: 1.14-1.38) in MZ pairs and 1.02 (95% CI: 0.94-1.11) in DZ pairs. The RR for strict IHS migraine in co-twins of probands reporting MDD was 2.23 (95% CI: 1.81-2.75) in MZ pairs and 1.55 (95% CI: 1.34-1.79) in DZ pairs; and the RR for MDD in co-twins of probands reporting IHS migraine was 1.35 (95% CI: 1.13-1.62) in MZ pairs and 1.06 (95% CI: 0.93-1.22) in DZ pairs.

CONCLUSIONS

We observed significant evidence for a genetic contribution to familial aggregation of migraine and depression. Our findings suggest a bi-directional association between migraine and depression, with an increased risk for depression in relatives of probands reporting migraine, and vice versa. However, the observed risk for migraine in relatives of probands reporting depression was considerably higher than the reverse. These results add further support to previous studies suggesting that patients with comorbid migraine and depression are genetically more similar to patients with only depression than patients with only migraine.

Migraine genetics: current findings and future lines of research

In the last two decades, migraine research has greatly advanced our current knowledge of the genetic contributions and the pathophysiology of this common and debilitating disorder. Nonetheless, this knowledge still needs to grow further and to translate into more effective treatments. To date, several genes involved in syndromic and monogenic forms of migraine have been identified, allowing the generation of animal models which have significantly contributed to current knowledge of the mechanisms underlying these rare forms of migraine. Common forms of migraine are instead posing a greater challenge, as they may most often stem from complex interactions between multiple common genetic variants, with environmental triggers. This paper reviews our current understanding of migraine genetics, moving from syndromic and monogenic forms to oligogenic/polygenic migraines most recently addressed with some success through genome-wide association studies. Methodological issues in study design and future perspectives opened by biomarker research will also be briefly addressed.

A genome-wide analysis of 'Bounty' descendants implicates several novel variants in migraine susceptibility

Migraine is a common neurological disease with a complex genetic aetiology. The disease affects ~12% of the Caucasian population and females are three times more likely than males to be diagnosed. In an effort to identify loci involved in migraine susceptibility, we performed a pedigree-based genome-wide association study of the isolated population of Norfolk Island, which has a high prevalence of migraine. This unique population originates from a small number of British and Polynesian founders who are descendents of the Bounty mutiny and forms a very large multigenerational pedigree (Bellis et al.; Human Genetics, 124(5):543-5542, 2008). These population genetic features may facilitate disease gene mapping strategies (Peltonen et al.; Nat Rev Genet, 1(3):182-90, 2000. In this study, we identified a high heritability of migraine in the Norfolk Island population (h (2) = 0.53, P = 0.016). We performed a pedigree-based GWAS and utilised a statistical and pathological prioritisation approach to implicate a number of variants in migraine. An SNP located in the zinc finger protein 555 (ZNF555) gene (rs4807347) showed evidence of statistical association in our Norfolk Island pedigree (P = 9.6 × 10(-6)) as well as replication in a large independent and unrelated cohort with >500 migraineurs. In addition, we utilised a biological prioritisation to implicate four SNPs, in within the ADARB2 gene, two SNPs within the GRM7 gene and a single SNP in close proximity to a HTR7 gene. Association of SNPs within these neurotransmitter-related genes suggests a disrupted serotoninergic system that is perhaps specific to the Norfolk Island pedigree, but that might provide clues to understanding migraine more generally.

Heritability and genome-wide linkage analysis of migraine in the genetic isolate of Norfolk Island

Migraine is a common neurovascular disorder with a complex envirogenomic aetiology. In an effort to identify migraine susceptibility genes, we conducted a study of the isolated population of Norfolk Island, Australia. A large portion of the permanent inhabitants of Norfolk Island are descended from 18th Century English sailors involved in the infamous mutiny on the Bounty and their Polynesian consorts. In total, 600 subjects were recruited including a large pedigree of 377 individuals with lineage to the founders. All individuals were phenotyped for migraine using International Classification of Headache Disorders-II criterion. All subjects were genotyped for a genome-wide panel of microsatellite markers. Genotype and phenotype data for the pedigree were analysed using heritability and linkage methods implemented in the programme SOLAR. Follow-up association analysis was performed using the CLUMP programme. A total of 154 migraine cases (25%) were identified indicating the Norfolk Island population is high-risk for migraine. Heritability estimation of the 377-member pedigree indicated a significant genetic component for migraine (h(2)=0.53, P=0.016). Linkage analysis showed peaks on chromosome 13q33.1 (P=0.003) and chromosome 9q22.32 (P=0.008). Association analysis of the key microsatellites in the remaining 223 unrelated Norfolk Island individuals showed evidence of association, which strengthen support for the linkage findings (P≤0.05). In conclusion, a genome-wide linkage analysis and follow-up association analysis of migraine in the genetic isolate of Norfolk Island provided evidence for migraine susceptibility loci on chromosomes 9q22.22 and 13q33.1.

Methylenetetrahydrofolate reductase gene variant (MTHFR C677T) and migraine: a case control study and meta-analysis

Background

Migraine is a common disorder that often coexists with depression. While a functional polymorphism in methyleneterahydrofolate reductase gene (MTHFR C677T) has been implicated in depression; the evidence to support an association of MTHFR with migraine has been inconclusive. We aim to investigate the effect of this variant on propensity for migraine and to perform a systematic review and meta-analysis of studies of MTHFR and migraine to date.

Methods

Individuals with migraine (n = 447) were selected from the Depression Case Control (DeCC) study to investigate the association between migraine and MTHFR C677T single nucleotide polymorphism (SNP) rs1801133 using an additive model compared to non-migraineurs adjusting for depression status. A meta-analysis was performed and included 15 studies of MTHFR and migraine.

Results

MTHFR C677T polymorphism was associated with migraine with aura (MA) (OR 1.31, 95% CI 1.01-1.70, p = 0.039) that remained significant after adjusting for age, sex and depression status. A meta-analysis of 15 case-control studies showed that T allele homozygosity is significantly associated with MA (OR = 1.42; 95% CI, 1.10-1.82) and total migraine (OR = 1.37; 95% CI, 1.07-1.76), but not migraine without aura (OR = 1.16; 95% CI, 0.36-3.76). In studies of non-Caucasian population, the TT genotype was associated with total migraine (OR= 3.46; 95% CI, 1.22-9.82), whereas in studies of Caucasians this variant was associated with MA only (OR = 1.28; 95% CI, 1.002-1.63).

Conclusions

MTHFR C677T is associated with MA in individuals selected for depression study. A meta-analysis of 15 studies supports this association and demonstrated effects across ethnic groups.

Selective Diffusion Changes of The Visual Pathways in Patients with Migraine: A 3-T Tractography Study

Using diffusion tensor (DT) tractography, we quantified optic radiation (OR) structural changes in seven migraine patients with (MA) and eight without visual aura (MoA) and their relation to clinical manifestations and T2-visible burden. The corticospinal tract and the corpus callosum were studied as ‘control’ white matter (WM). No difference was found for any of the WM fibre bundles metrics between controls and MoA patients. MA patients had reduced average fractional anisotropy (FA) of both OR compared with controls and reduced average FA of the right OR compared with MoA patients. They also showed higher right OR mean diffusivity than controls. OR metrics were not correlated with clinical and magnetic resonance imaging (MRI) metrics. DT tractography reveals OR changes in MA patients that might represent a phenotypic biomarker of the disease given the lack of correlation with clinical and structural MRI metrics.

Familial risks for common diseases: etiologic clues and guidance to gene identification

Familial clustering of a disease is a direct indicator of a possible heritable cause, provided that environmental sharing can be excluded. If the familial clustering is lacking, the likelihood of a heritable influence is also small. In the era of genome scans, the consideration of data on heritability should be important in the assessment of the likely success of the genome scan. The availability of a Multigeneration Register in Sweden provides a reliable access to families throughout the last century. This Register has been extensively used to study a number of different diseases through linkage to the Hospital Discharge Register. In the present article we review the obtained and some unpublished results for nine main disease classes. For each of these, familial risks are given for four disease subtypes. As measures of familial clustering we use risks between siblings, twins and spouses. Disease correlation between spouses suggests environmental sharing and a higher correlation between siblings and particularly twins shows heritable effects. We will also comment on the established susceptibility genes and the risks conferred by them. The data suggest high heritabilities for chronic obstructive pulmonary disease, asthma, noninfective enteritis and colitis, cerebral palsy and endocrine and metabolic diseases. Among the performed first-generation genome scans on various diseases, the success appears to be related to the a priori heritability estimates. To our knowledge this is a first attempt to summarize familial risks for a large number of diseases using data from a single population on which reasonable uniform diagnostic criteria have been applied.

Genetic biomarkers for migraine

Biomarkers are physical signs or laboratory measurements that occur in association with a pathological process and have putative diagnostic and/or prognostic utility. In migraine, clinical, radiological, and biochemical biomarkers might be helpful to improve diagnosis, get insight in pathophysiology, and facilitate treatment choices. Genetic biomarkers are defined as genetic variations (mutations or polymorphisms) that can predict disease susceptibility, disease outcome, or treatment response. As yet, only a few genetic biomarkers for migraine are available. Mutations in 3 different genes responsible for familial hemiplegic migraine, a monogenetic subtype of migraine with aura, and the MTHFR C677T polymorphism in common forms of migraine are clear examples. Many positive findings from linkage studies and association studies in common forms of migraine have not been replicated, and are therefore of less clinical use. In this review, we will discuss genetic biomarkers in migraine.

Orofacial Pain--Part II: Assessment and management of vascular, neurovascular, idiopathic, secondary, and psychogenic causes

Chronic orofacial pain is a common health complaint faced by health practitioners today and constitutes a challenging diagnostic problem that often requires a multidisciplinary approach to diagnosis and treatment. The previous article by the same authors in this issue discussed the major clinical characteristics and the treatment of various musculoskeletal and neuropathic orofacial pain conditions. This second article presents aspects of vascular, neurovascular, and idiopathic orofacial pain, as well as orofacial pain due to various local, distant, or systemic diseases and psychogenic orofacial pain. The emphasis in this article is on the general differential diagnosis and various therapeutic regimens of each of these conditions. An accurate diagnosis is the key to successful treatment of chronic orofacial pain. Given that for many of the entities discussed in this article no curative treatment is available, current standards of management are emphasized. A comprehensive reference section has been included for those who wish to gain further information on a particular entity.

Familial risks for migraine and other headaches among siblings based on hospitalizations in Sweden

Migraine and other headaches are common disabling conditions, reducing the quality of life in the affected individuals. The unambiguous definition of familial risk for subtypes of migraine and other headaches will advance the search for the heritable causes of these conditions and their underlying mechanisms. We aim at defining familial risks for siblings to be hospitalized because of migraine or other headaches. An ad hoc migraine database was constructed by linking the Multigeneration Register on 0- to 69-year-old siblings to the Hospital Discharge Register for data on migraines of all hospitalized patients in Sweden from years 1987 to 2001. Standardized incidence ratios (SIRs) were calculated for affected sibling pairs by comparison with those whose siblings had no migraine. Among a total of 14,123 hospitalized patients, 205 affected siblings were identified, with a familial SIR of 2.84. SIRs for migraine with and without aura were 3.08 and 2.67, respectively. The highest familial risk of 3.71 was noted for unspecified migraine. The risk tended to be higher for concordant (both siblings sharing the migraine subtype, ranging from 4.0 to 6.0) than discordant subtypes, but even many discordant SIRs were significant. The SIR for spouse correlation was 1.14 for husbands and 1.22 for wives, far from being significant. All subtypes of hospitalized migraines and other headaches show an increased familial risk, at least in specific age groups. The different subtypes appear to share susceptibility, which may imply common disease mechanisms.

Recent findings in headache genetics

PURPOSE OF REVIEW

The progress in headache genetics, especially migraine genetics, recently jumped ahead with some major discoveries.

RECENT FINDINGS

Family and epidemiological studies further strengthen the genetic contribution to migraine and two recent observations gave new molecular insights in the disease. Studies on the genetics of familial hemiplegic migraine revealed, in addition to the previously identified familial hemiplegic migraine type 1 gene CACNA1A on chromosome 19, the familial hemiplegic migraine type 2 gene ATP1A2, encoding the alpha2-subunit of sodium/potassium pumps. Recent genome screens in families with migraine identified susceptibility loci on chromosomes 4, 6, 11 and 14.

SUMMARY

The findings in familial hemiplegic migraine confirm that dysfunction in ion transport is a key factor in migraine pathophysiology and might help us in the elucidation of migraine molecular pathways. The identification of several migraine susceptibility loci underline its genetically complex nature.

Migraine: an ophthalmologist's perspective

PURPOSE OF REVIEW

Migraine is a common disorder with visual and neurologic manifestations. Many patients present to ophthalmologists without a previous diagnosis of migraine. It is therefore essential for the ophthalmologist to have a good understanding of migraine to appropriately help these patients. Neurologic syndromes with migraine and retinopathy are well known. Here again, the ophthalmologist may play a role in establishing the correct diagnosis.

RECENT FINDINGS

For long the initial changes during a migraine attack have been shown to occur in the occipital cortex. In the recent years, the understanding of migraine has advanced with the availability of functional neuroimaging. A possible role of brainstem structures in the initiation of migraine attacks has been proposed based on functional magnetic resonance imaging blood oxygenation level-dependent signals. Activation of brainstem structures preceded activation of occipital cortex. Our understanding of cortical spreading depression is also advancing. Using multiwavelength optical intrinsic imaging, cortical spreading depression has been shown to have a triphasic response in rats. For the first time it has been shown that the cortical spreading depression activated the trigeminovascular system, which is followed by a series of cortical meningeal and brainstem events that cause the migraine headache. Sildenafil has been shown to induce migraine attack without dilation of cerebral blood vessels, further confirming that Wolf's vasogenic theory may not be true. Several loci for migraine have been identified in recent years. A new locus for migraine with and without aura has been identified on chromosome 6, a locus for migraine without aura to chromosome 14, and a locus for migraine with aura on chromosome 4.

SUMMARY

Our understanding of migraine is rapidly evolving with functional neuroimaging. There are several unanswered questions. In this article, we will review the epidemiology, genetics, and clinical features of various forms of migraine with emphasis on ocular migraine, pathogenesis, and briefly the management of migraine.