Migraine: disease characterisation, biomarkers, and precision medicine

Migraine is a disabling neurological disorder, diagnosis of which is based on clinical criteria. A shortcoming of these criteria is that they do not fully capture the heterogeneity of migraine, including the underlying genetic and neurobiological factors. This complexity has generated momentum for biomarker research to improve disease characterisation and identify novel drug targets. In this Series paper, we present the progress that has been made in the search for biomarkers of migraine within genetics, provocation modelling, biochemistry, and neuroimaging research. Additionally, we outline challenges and future directions for each biomarker modality. We also discuss the advances made in combining and integrating data from multiple biomarker modalities. These efforts contribute to developing precision medicine that can be applied to future patients with migraine.

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.

Clinical features of chronic cluster headache based on the third edition of the International Classification of Headache Disorders: A prospective multicentre study

The criterion for the remission period of chronic cluster headache (CCH) was recently revised from < 1 month to < 3 months in the third edition of the International Classification of Headache Disorders (ICHD-3). However, information on the clinical features of CCH based on the ICHD-3 criteria is currently limited. The present study aimed to investigate the clinical features of CCH based on ICHD-3 using data from the Korean Cluster Headache Registry (KCHR). The KCHR is a multicentre prospective registry of patients with cluster headache (CH) from 15 hospitals. Among the 250 participants with CH, 12 and 176 participants were classified as having CCH and episodic cluster headache (ECH), respectively. Among 12 participants with CCH, 6 (50%) had remission periods of < 1 month, and the remaining 6 (50%) had a remission period of 1–3 months. Six participants had CCH from the time of onset of CH, and in the other 6 participants, CCH evolved from ECH. CCH subjects had later age of onset of CH, developed the condition after a longer interval after CH onset, and had more migraine and less nasal congestion and/or rhinorrhoea than ECH subjects. Clinical features of CCH with remission periods < 1 month were not significantly different from those of CCH with remission periods of 1–3 months, except for the total number of bouts. More current smoking and less diurnal rhythmicity were observed in participants with CCH evolved from ECH compared to those with ECH. In conclusion, the number of subjects with CCH doubled when the revised ICHD-3 criteria were used. Most of clinical characteristics of CCH did not differ when the previous and current version of ICHD was applied and compared. Some clinical features of CCH were different from those of ECH, and smoking may have a role in CH chronification.

Migraine burden and costs in France: a nationwide claims database analysis of triptan users

Objectives: To estimate the burden of migraine in the population of French patients identified as specific migraine acute treatment users compared to a control group. Methods: A cross-sectional retrospective analysis was performed on the Echantillon Généraliste des Bénéficiaires claims database, a 1/97 random sample of the French public insurance database. A representative sample of all adults with at least one delivery of triptans, ergot derivatives or acetylsalicylic acid/metoclopramide (all drugs with a specific label in migraine acute treatment - SMAT) in 2014 was selected with a control group matched on age, gender and geographic region. Among triptan users, a sub-group of over-users was defined according to their level of triptan uptake expressed in defined daily doses (DDD - a standard daily dose of treatment of acute migraine) per month over 3 months and more, was also compared with controls. The cost analysis was performed in a societal perspective for direct costs. Sick leave indirect costs were estimated using the human capital approach. Results: In total 8639 SMAT users (mean age: 44.6 years; 78.7% women) were selected representing a crude prevalence rate of 1.7%. The annual per capita total healthcare expenditures were higher by €280 in this group compared to controls (€2463 vs. €2183). Triptans contributed 47.8% to this extra cost. They used significantly (p < .0001) more frequently than controls antidepressants (20.8% vs. 11.0%), anxiolytics (29.4% vs. 18.8%) and analgesics (53.8% vs. 35.8%). The per capita annual productivity loss associated with sick leave was higher by €295 (€1712 vs. €1417). Among triptan users, there were 2.9% over-users. This last group was characterized by substantially higher per capita annual extra direct (+ €1805) and indirect costs (productivity loss +€706) compared to controls. Conclusions: Due to its high prevalence, migraine costs generate a significant societal burden. The group of over-users concentrates high per capita direct and indirect costs.

Quantifying visual allodynia across migraine subtypes: the Leiden Visual Sensitivity Scale

Enhanced sensitivity to light (photophobia) and patterns is common in migraine and can be regarded as visual allodynia. We aimed to develop and validate a questionnaire to easily quantify sensitivity to light and patterns in large populations, and to assess and compare visual allodynia across different migraine subtypes and states. We developed the Leiden Visual Sensitivity Scale (L-VISS), a 9-item scale (score range 0-36 points), based on literature and patient interviews, and examined its construct validity. Furthermore, we assessed ictal and interictal visual sensitivity in episodic migraine with (n = 67) and without (n = 66) aura and chronic migraine with (n = 20) and without (n = 19) aura, and in healthy controls (n = 86). Differences between migraine subtypes and states were tested using a linear mixed model with 3 fixed factors (episodic/chronic, with/without aura, and ictal/interictal). Test-retest reliability and construct validity of L-VISS were good. Leiden Visual Sensitivity Scale scores correlated in the expected direction with light discomfort (Kendall's τ = -0.25) and pattern glare tests (τ = 0.35). Known-group comparisons confirmed its construct validity. Within migraine subtypes, L-VISS scores were higher in migraine with aura versus without aura and in chronic versus episodic migraine. The linear mixed model showed all factors affected the outcome (P < 0.001). The L-VISS is an easy-to-use scale to quantify and monitor the burden of bothersome visual sensitivity to light and patterns in large populations. There are remarkable ictal and interictal differences in visual allodynia across migraine subtypes, possibly reflecting dynamic differences in cortical excitability.

Experts' opinion about the primary headache diagnostic criteria of the ICHD-3rd edition beta in children and adolescents

BACKGROUND

The 2013 International Classification of Headache Disorders-3 (ICHD-3) was published in a beta version to allow the clinicians to confirm the validity of the criteria or to suggest improvements based on field studies. The aim of this work was to review the Primary Headache Disorders Section of ICHD-3 beta data on children and adolescents (age 0-18 years), and to suggest changes, additions, and amendments.

METHODS

Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the literature available on pediatric headache, they made observations and proposed suggestions for the primary headache disorders section of ICHD-3 beta data on children and adolescents.

RESULTS

Some headache disorders in children have specific features which are different from those seen in adults and which should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psycho-social basis in children and adolescents making primary headache disorders in children distinct from those in adults.

CONCLUSIONS

Several recommendations are presented in order to make ICHD-3 more appropriate for use with children.

Classification of common human diseases derived from shared genetic and environmental determinants

In this study, we used insurance claims for over one-third of the entire US population to create a subset of 128,989 families (481,657 unique individuals). We then used these data to (i) estimate the heritability and familial environmental patterns of 149 diseases and (ii) infer the genetic and environmental correlations for disease pairs from a set of 29 complex diseases. The majority (52 of 65) of our study's heritability estimates matched earlier reports, and 84 of our estimates appear to have been obtained for the first time. We used correlation matrices to compute environmental and genetic disease classifications and corresponding reliability measures. Among unexpected observations, we found that migraine, typically classified as a disease of the central nervous system, appeared to be most genetically similar to irritable bowel syndrome and most environmentally similar to cystitis and urethritis, all of which are inflammatory diseases.

[Clinical characteristics of vestibular migraine: considerations in a series of 41 patients]

INTRODUCTION

After years of debate about its being approached from headaches and its denomination, vestibular migraine has recently been included in the research appendix of the 3rd edition of the International Headache Classification.

AIM

To analyse the characteristics of a series of patients with vestibular migraine who visited because of headaches.

PATIENTS AND METHODS

Our sample consisted of patients who were attended in a headache unit between January 2014 and December 2015. The demographic variables and the characteristics of both migraine and vestibular symptoms were considered, and cases with other otorhinolaryngological conditions were excluded.

RESULTS

The sample was finally made up of 41 patients (11 males, 30 females) with a mean age of 31.8 ± 13.3 years at the time they were included in the study. Sixteen patients (39%) met criteria for chronic migraine and two (4.9%) presented visual auras. The vestibular symptoms were considered severe in eight cases (19.5%) and occurred in 74.6% of the migraine attacks. Vertigo was described as internal in 18 cases (43.9%), external in 22 (53.7%) and mixed in one case (2.4%). The most frequent symptom was positional vertigo (n = 25; 61%), followed by that induced by head movements (n = 18; 43.9%) and spontaneous (n = 15; 36.6%). Accompanying symptoms included tinnitus (n = 12; 29.3%) and a feeling of fullness in the ear (n = 8; 19.5%).

CONCLUSION

It is not uncommon to identify symptoms consistent with vestibular migraine in patients who visit a headache unit; they are patients whose day-to-day activities are not usually affected by their vertigo.

Field testing of the ICHD-3β and expert opinion criteria for chronic migraine

BACKGROUND

Chronic headache (CrH) occurs commonly in the population, and chronic migraine (CM) accounts for much of the CrH. Diagnostic criteria for CM remain controversial, and this could lead to undertreatment of CM. The purpose of this study was to analyze the clinical profiles of CM and to field test the International Classification of Headache Disorders-3β criteria (ICHD-3β) and Expert Opinion criteria (EO) for CM application.

METHODS

We retrospectively reviewed the medical records of CrH patients in our headache clinic during the period. Eligible patients were selected from CrH population based on Silberstein and Lipton criteria (S-L) for CM, and meanwhile fulfilled with migraine days at least 8 days/month. Then we evaluated the characteristics of clinic profiles and outcomes between patients diagnosed CM using ICHD-3β and EO criteria. Field tested the CM criteria Of ICHD-3β and EO.

RESULTS

In a total of 710 CrH patients , 261 (36.8 %) were recruited with CM based on both S-L criteria and fulfilled at least 8 migraine days/month. Be understandable, all the 261 patients met the EO criteria, and only 185 (70.9 %) met ICHD-3β for CM. For the 76 patients who met EO but not ICHD-3β, 70 had atypical migraine attacks (probable migraine, PM), and another 6 had typical migraine attacks but less than a total history of 5 attacks. Although 173 (66.3 %) were concurrent with medication overuse, just one patient overused triptans and none used ergot agents. Clinical features were not significantly different between the ICHD-3β and EO criteria groups (P > 0.05), and neither were outcomes of prophylaxis (P = 0.966). Total migraine prophylaxis effectiveness was 73 %.

CONCLUSION

Migraine-specific analgesics are rarely used in China, permitting patients with PM to avail themselves of "migraine days" is a reasonable accommodation for this difficult condition. In our hands, use of the new EO criteria for diagnosis of CM increases the sensitivity and maintains the specificity of decision making, and therefore should be adopted in CM management practice.

Migraine Days Decline with Duration of Illness in Adolescents with Transformed Migraine

The aim of this study was to assess the proportion of subjects with transformed migraine (TM) who have 15 or more migraine days per month as a function of duration of chronic daily headache (CDH) in an adolescent sample. CDH is a syndrome characterized by 15 or more headache days per month. In specialty care, TM is the most common type of CDH. Most adults who meet criteria for TM do not meet the International Headache Society (IHS) criteria for chronic migraine (CM). TM criteria require 15 or more headache days per month (not necessarily migraine), with a current or past history of migraine. CM requires 15 or more migraine days per month. As TM develops, attack frequency increases and the number of migraine features diminishes. If this observation is correct, individuals who meet criteria for TM but not CM may be at a later stage in the evolution of the disease, compared with those who meet criteria for CM. We reviewed charts of 267 adolescents (13-17 years) seen in a headache centre, to identify 117 with TM. We divide subjects with TM into those with recent onset (1 year) vs. longer duration (>1 year) and examined the number of migraine days per month and demographic features. We modelled predictors of CM (>15 migraine days per month) using logistic regression. Of 117 adolescents with TM, 55 (47%) had recent-onset (<1 year) and 62 (53%) had long-duration TM. Those with recent-onset TM were much more likely also to meet criteria for CM (74.5% vs. 25.8%, P < 0.001). This was verified in the TM with medication overuse subgroup (recent onset 66.7%, vs. long duration 37%, P = 0.01) and in the TM without medication overuse subgroup (62.2% vs. 19.2%, P = 0.001). Modelling the dichotomous outcome of CM (>15 days of migraine/month) in logistic regression, CM was predicted by recent onset of CDH, recent onset of migraine (<36 months), and younger ages (15 years), but not gender or use of migraine preventive drugs or medication overuse. Among adolescents with TM, CM is more likely in individuals who are young, whose episodic headache began recently, and with CDH of recent onset. These findings suggest that early in the process of transformation, migraine is more frequent, and that as CDH evolves, fewer typical attacks of IHS migraine occur.

Clinical Features of Migraine: A Cross-Sectional Study in Patients Aged Three to Sixty-Nine

We investigated 260 consecutive patients classified as migraine cases aged 3-69 at two tertiary headache centres, one for children and adolescents and the other for adults to evaluate the relationship between age and clinical features of migraine cross-sectionally. We only included subjects with definite migraine without or with aura and we excluded subjects with coexisting tension-type headache, medication overuse and/or other clinically relevant disorders. The percentage of males decreased markedly from childhood to adulthood and this affected the evalution of age-related changes in male patients, as only large differences reached the level of statistical significance. In females, the headache duration and the prevalence of unilateral, pulsating pain, photophobia and phonophobia increased, whereas the prevalence of aggravation by physical activity decreased with age. In conclusion, this cross-sectional, clinic-based study on a strictly defined sample of 260 consecutive patients with definite migraine covering a wide range of age from the very young to the old suggests marked age-related differences of the clinical features of migraine in females and failed to demonstrate similar differences in males due to the small number of adult male migraineurs.

The Aura: A Tertiary Care Study of 952 Migraine Patients

The aim of this study was to document the frequency and types of aura symptoms, to define the relationship between aura symptoms and to define the aura frequency in different migraine types. In 952 migraine patients, aura frequency, duration, time to headache, characteristics and percentage of headaches with aura were analysed. Thirty-eight percent of IHS 1.1-1.5 patients reported aura, 38.1% of females and 33.0% of males. Average percentage of aura occurrence with headache was 19.7% of headaches, average aura duration 27.3 min and aura was followed by headache in 10.4 min on average. Visual disturbances occurred in 92.1% and aura without visual aura was rare. Aura frequency was headache-type dependent. The highest frequency of aura was seen in the more ‘full-blown’ migraine attack. Visual aura is the overwhelming aura symptom. Even in patients with aura the percentage of aura with migraine attacks is limited.

Headache Prevention Outcome and Body Mass Index

A population-based longitudinal study suggests that obesity is a strong risk factor for the development of headaches on 15 or more days per month. Little is know about the influence of weight on the response to headache preventive treatment. Herein we prospectively assessed the influence of the baseline body mass index (BMI) on the response to headache preventive treatment. We included adults with episodic or chronic migraine (ICHD-2), or transformed migraine (Silberstein and Lipton criteria) that sought care in a headache clinic. BMI was assessed in the first visit. Baseline information included headache frequency, number of days with severe headache (prospectively obtained over 1 month), and headache-related disability (HIT-6). The same information was obtained after 3 months of preventive treatment. Subjects were categorized based on BMI in: normal weight (≤24.9), overweight (25-29.9), or obese (≥30). We contrasted the headache end-points using ANOVA with post-test and Kruskal-Wallis with post-test. We used logistic regression to model BMI and headache parameters adjusting for covariates. Our sample consisted of 176 subjects (79.5% women, mean of 44.4 years). At baseline 40.9% had normal weight, 29.5% were overweight and 27.3% were obese. No significant differences were observed in the number of headache days at baseline. After treatment, frequency declined in the entire population, but no significant differences were found by BMI group. Regarding the number of days with severe pain per month, there were also no significant differences at baseline (normal = 6.1, overweight = 6.5, obese = 6.7), and improvement overall ( P = 0.01). However, changes were greater in the obese (reduction in 2.7 days with treatment) and overweight (3.9) vs. normal (1.5, P < 0.01). Finally, HIT scores at baseline did not differ by BMI group (normal weight = 63.8, overweight = 64.1, obese = 63.6). However, compared with the normal weighted group, change in HIT scores (followup baseline) were greater in the obese (6.4 vs. 3.5, P < 0.05) and overweight groups (6.8 vs. 3.5, P < 0.05). In the logistic regression model, BMI did not account for changes in disability, headache frequency, or in the number of days with severe headache per month, after adjusting for covariates. Contrary to what we hypothesized, obesity at baseline does not seem to be related to follow-up refractoriness to preventive treatment.

Cluster Headache and Paroxysmal Hemicrania: Differential Diagnosis

The utility of the differences between cluster headache (CH) and paroxysmal hemicrania (PH) is limited by the considerable overlap of their clinical characteristics. We compared 54 patients with CH and eight patients with PH in terms of demographic features, characteristics of headache attacks, associated autonomic features, temporal forms of disorders, and response to verapamil. According to our results, clinical features that distinguished CH and PH patients were: maximal pain localization, ocular in CH patients and extra-ocular in PH group; mean attack duration was longer and mean attack frequency was lower in CH patients in comparison with PH patients. Conjuctival injection was the only autonomic sign seen more frequently in CH patients. There were more CH patients with episodic and more PH patients with unremitting form of the disorder in examined groups. Although statistical analysis pointed out a significant difference between these clinical features, there was no clinical characteristic that exclusively belonged to one of these headache entities. Demographic characteristics (age, gender, social background), the other headache attack features (nocturnal attacks, interattack tenderness), the other autonomic signs, as well as the response to verapamil did not differ significantly between two groups.

The International Classification of Headache Disorders Revised Criteria for Chronic Migraine—Field Testing in a Headache Specialty Clinic

In the absence of a biological marker and expert consensus on the best approach to classify chronic migraine (CM), recent revised criteria for this disease has been proposed by the Headache Classification Committee of the International Headache Society. This revised criteria for CM is now presented in the Appendix. Herein we field test the revised criteria for CM. We included individuals with transformed migraine with or without medication overuse (TM+ and TM-), according to the criteria proposed by Silberstein and Lipton, since this criterion has been largely used before the Second Edition of the International Classification of the Headache Disorders (ICHD-2). We assessed the proportion of subjects that fulfilled ICHD-2 criteria for CM or probable chronic migraine with probable medication overuse (CM+), as well as the revised ICHD-2 (ICHD-2R) criteria for CM (≥15 days of headache, ≥8 days of migraine or migraine-specific acute medication use—ergotamine or triptans). We also tested the ICHD-2R vs. three proposals. In proposal 1, CM/CM+ would require at least 15 days of migraine or probable migraine per month. Proposal 2 required ≥15 days of headache per month and at least 50% of these days were migraine or probable migraine. Proposal 3 required ≥15 days of headache and at least 8 days of migraine or probable migraine per month. Of the 158 patients with TM-, just 5.6% met ICHD-2 criteria for CM. According to the ICHD-2R, a total of 92.4% met criteria for CM ( P < 0.001 vs. ICHD-2). The ICHD-2R criterion performed better than proposal 1 (47.8% of agreement, P < 0.01) and was not statistically different from proposals 2 (87.9%) and 3 (94.9%). Subjects with TM+ should be classified as medication overuse headache (MOH), and not CM+, according to the ICHD-2R. Nonetheless, we assessed the proportion of them who had ≥8 days of migraine per month. Of the 399 individuals with TM+, just 10.2% could be classified as CM+ in the ICHD-2. However, most (349, 86.9%) had ≥8 days of migraine per month and could be classified as MOH and probable CM in the ICHD-2R ( P < 0.001 vs. ICHD-2). We conclude that the ICHD-2R addresses most of the criticism towards the ICHD-2 and should be adopted in clinical practice and research. In the population where use of specific acute migraine medications is less common, the agreement between ICHD-2R CM and TM may be less robust.

The Place of Osmophobia and Taste Abnormalities in Migraine Classification: A Tertiary Care Study of 1237 Patients

This study evaluates osmophobia and taste abnormalities in relationship to sensitivity and specificity in the classification of migraine. Consecutive International Headache Society (IHS) classified patients ( n = 1237) were evaluated. Symptoms were graded from 0 to 3. Osmophobia and taste abnormalities were tested for sensitivity and specificity in migraine diagnosis. The patients were 85.4% female and their mean age was 38.1 years. Of 673 patients 24.7% complained of osmophobia, and 24.6% of 505 complained of taste abnormalities. In the absence of nausea and vomiting the combinations of two symptoms gave the following sensitivity and specificity percentages, respectively: photophobia and phonophobia, 10.6 and 84.9; photophobia and osmophobia, 1.1 and 99.0; phonophobia and osmophobia, 1.1 and 98.6; photophobia and taste abnormality, 9.6 and 99.0; phono-phobia and taste abnormality, 9.6 and 98.8; and osmophobia and taste abnormality, 4.2 and 99.4. Osmophobia and taste abnormalities were demonstrated to be very specific in diagnosing migraine IHS 1.1-1.6, but very insensitive.

Cervical Musculoskeletal Impairment in Frequent Intermittent Headache. Part 1: Subjects With Single Headaches

Musculoskeletal disorders are considered the underlying cause of cervicogenic headache, but neck pain is commonly associated with migraine and tension-type headaches. This study tested musculoskeletal function in these headache types. From a group of 196 community-based volunteers with headache, 73 had a single headache classifiable as migraine ( n = 22), tension-type ( n = 33) or cervicogenic headache ( n = 18); 57 subjects acted as controls. Range of movement, manual examination of cervical segments, cervical flexor and extensor strength, the cranio-cervical flexion test (CCFT), cross-sectional area of selected extensor muscles at C2 (ultrasound imaging) and cervical kinaesthetic sense were measured by a blinded examiner. In all but one measure (kinaesthetic sense), the cervicogenic headache group were significantly different from the migraine, tension-type headache and control groups (all P < 0.001). A dicriminant function analysis revealed that collectively, restricted movement, in association with palpable upper cervical joint dysfunction and impairment in the CCFT, had 100% sensitivity and 94% specificity to identify cervicogenic headache. There was no evidence that the cervical musculoskeletal impairments assessed in this study were present in the migraine and tension-type headache groups. Further research is required to validate the predictive capacity of this pattern of impairment to differentially diagnose cervicogenic headache.

Changing Headache from Preschool Age to Puberty. A Controlled Study

The characteristics of disturbing primary headache and the occurrence of headache types were studied by sending a questionnaire to 1132 Finnish families of 6-year-old children. Children with headache in the preceding 6 months and their controls were clinically examined at the ages of 6 and 13. During the follow-up, half of the headaches, classified as migraine at age 6 years, were unchanged and 32% turned into tension-type headache. In children with tension-type headache, the situation was unchanged in 35%, and in 38% of children the headache type had changed to migraine. At preschool age the most common location of headache was bilateral and supraorbital, and at puberty bilateral and temporal. During the follow-up, symptoms concurrent with headache, such as odour phobia, dizziness and balance disturbances became more typical, whereas restlessness, flushing and abdominal symptoms became less marked. The early manifestation of both migraine and tension-type headache predict equally often migraine in puberty with marked changes in concurrent symptoms and pain localization.

Migraine — New Perspectives from Chaos Theory

Converging from a number of disciplines, non-linear systems theory and in particular chaos theory offer new descriptive and prescriptive insights into physiological systems. This paper briefly reviews an approach to physiological systems from these perspectives and outlines how these concepts can be applied to the study of migraine. It suggests a wide range of potential applications including new approaches to classification, treatment and pathophysiological mechanisms. A hypothesis is developed that suggests that dysfunctional consequences can result from a mismatch between the complexity of the environment and the system that is seeking to regulate it and that the migraine phenomenon is caused by an incongruity between the complexity of mid brain sensory integration and cortical control networks. Chaos theory offers a new approach to the study of migraine that complements existing frameworks but may more accurately reflect underlying physiological mechanisms.

Psychiatric Comorbidity in the Evolution From Migraine to Medication Overuse Headache

We set out to study the role of psychiatric comorbidity in the evolution of migraine to medication overuse headache (MOH) by a comparative study of 41 migraineurs (MIG) and 41 patients suffering from MOH deriving from migraine. There was an excess risk of suffering from mood disorders [odds ratio (OR) = 4.5, 95% confidence interval (CI) 1.5, 13.5], anxiety (OR = 5, 95% CI 1.2, 10.7) and disorders associated with the use of psychoactive substances other than analgesics (OR = 7.6, 95% CI 2.2, 26.0) in MOH compared with MIG. Retrospective study of the order of occurrence of disorders showed that in the MOH group, psychiatric disorders occurred significantly more often before the transformation from migraine into MOH than after. There was no crossed-family transmission between MOH and psychiatric disorders, except for substance-related disorders. MOH patients have a greater risk of suffering from anxiety and depression, and these disorders may be a risk factor for the evolution of migraine into MOH. Moreover, MOH patients have a greater risk of suffering from substance-related disorders than MIG sufferers. This could be due to the fact that MOH is part of the spectrum of addictive disorders.

Comprehensive Application of the International Classification of Headache Disorders Third Edition, Beta Version

The purpose of this study was to test the feasibility and usefulness of the International Classification of Headache Disorders, third edition, beta version (ICHD-3β), and compare the differences with the International Classification of Headache Disorders, second edition (ICHD-2). Consecutive first-visit patients were recruited from 11 headache clinics in Korea. Headache classification was performed in accordance with ICHD-3β. The characteristics of headaches were analyzed and the feasibility and usefulness of this version was assessed by the proportion of unclassified headache disorders compared with ICHD-2. A total of 1,627 patients were enrolled (mean age, 47.4±14.7 yr; 62.8% female). Classification by ICHD-3β was achieved in 97.8% of headache patients, whereas 90.0% could be classified by ICHD-2. Primary headaches (n=1,429, 87.8%) were classified as follows: 697 migraines, 445 tension-type headaches, 22 cluster headaches, and 265 other primary headache disorders. Secondary headache or painful cranial neuropathies/other facial pains were diagnosed in 163 patients (10.0%). Only 2.2% were not classified by ICHD-3β. The main reasons for missing classifications were insufficient information (1.6%) or absence of suitable classification (0.6%). The diagnoses differed from those using ICHD-2 in 243 patients (14.9%). Among them, 165 patients were newly classified from unclassified with ICHD-2 because of the relaxation of the previous strict criteria or the introduction of a new diagnostic category. ICHD-3β would yield a higher classification rate than its previous version, ICHD-2. ICHD-3β is applicable in clinical practice for first-visit headache patients of a referral hospital.

Selectivity in genetic association with sub-classified migraine in women

Migraine can be sub-classified not only according to presence of migraine aura (MA) or absence of migraine aura (MO), but also by additional features accompanying migraine attacks, e.g. photophobia, phonophobia, nausea, etc. all of which are formally recognized by the International Classification of Headache Disorders. It remains unclear how aura status and the other migraine features may be related to underlying migraine pathophysiology. Recent genome-wide association studies (GWAS) have identified 12 independent loci at which single nucleotide polymorphisms (SNPs) are associated with migraine. Using a likelihood framework, we explored the selective association of these SNPs with migraine, sub-classified according to aura status and the other features in a large population-based cohort of women including 3,003 active migraineurs and 18,108 free of migraine. Five loci met stringent significance for association with migraine, among which four were selective for sub-classified migraine, including rs11172113 (LRP1) for MO. The number of loci associated with migraine increased to 11 at suggestive significance thresholds, including five additional selective associations for MO but none for MA. No two SNPs showed similar patterns of selective association with migraine characteristics. At one extreme, SNPs rs6790925 (near TGFBR2) and rs2274316 (MEF2D) were not associated with migraine overall, MA, or MO but were selective for migraine sub-classified by the presence of one or more of the additional migraine features. In contrast, SNP rs7577262 (TRPM8) was associated with migraine overall and showed little or no selectivity for any of the migraine characteristics. The results emphasize the multivalent nature of migraine pathophysiology and suggest that a complete understanding of the genetic influence on migraine may benefit from analyses that stratify migraine according to both aura status and the additional diagnostic features used for clinical characterization of migraine.

Migraine is among the most common and debilitating neurological disorders. Diagnostic criteria for migraine recognize a variety of symptoms including a primary dichotomous classification for the presence or absence of aura, typically a visual disturbance phenomenon, as well as others such as sensitivity to light or sound, and nausea, etc. We explored whether any of 12 recently discovered genetic variants associated with common migraine might have selective association for migraine sub-classified by aura status or nine additional migraine features in a population of middle-aged women including 3,003 migraineurs and 18,180 non-migraineurs. Five of the 12 genetic variants met the most stringent significance criterion for association with migraine, among which four had selective association with sub-classified migraine, including one that was selective for migraine without aura. At suggestive significance, all of the remaining genetic variants were selective for sub-classifications of migraine although no two variants showed the same pattern of selectivity. The selectivity patterns suggest very different contributions to migraine pathophysiology among the 12 loci and their implicated genes. Further, the results suggest that future discovery efforts for new migraine susceptibility loci would benefit by considering associations with sub-classified migraine toward the ultimate goals of more specific diagnosis and personalized treatment.

[Systematization of primary headache: current and future prospects]

The article is devoted to the current state of the problem of systematization of primary headaches and main clinical forms. The conceptual evolution of ideas about the classification of certain options of cephalgia and identified major trends for its improvement is given. Verification of types and subtypes of individual cephalgia can present a significant challenge even for experienced neurologists, neurosurgeons, and internists. In this regard in most European countries and the US. have set up specialized centers for the treatment of headaches. Concluded that in the short term in the national health care system, including. Including the Armed Forces, it is advisable to create such centers.

[New classification and standards in treatment of migraine]

Diagnosis of migraine is performed according to the International Classification of Headache Disorders (ICHD). A current version is ICHD-2004 (2 ed.). A new addition of ICHD beta-version has been published in 2013. This article reviews the structure of the new classification and main criteria of different types of headache. Main treatment approaches and features of some drugs for treatment of headache and migraine are considered. Special attention is focused on xefocam, a nonsteroidal anti-inflammatory drug.

[Migraine: ignition of the brain]

Although our knowledge of which systems are activated during migraine is reasonably complete, why the system is activated remains unknown. Incorporating the findings obtained in studies on pain in general has allowed a more integrated model to be generated. According to this new model, there is an anatomical substrate consisting in a complex framework of pain that is made up not only of the trigeminovascular system (end pathway) but of a number of networks that are in turn connected to one another, like the neurolimbic, the ascending and descending modulatory system. This complex network is responsible for modulating and conveying nociceptive signals. In patients with migraine, hyperexcitability of this framework is conditioned by genetic and epigenetic alterations. Epigenetic changes are chemical modifications affecting chromatin, which modulates the activity of genes without modifying the DNA sequence, and which are capable of modulating the expression of genes involved in a number of different aspects, such as plasticity, system excitability, memory of pain or moods. In turn, the presence of external factors (such as environmental changes or alcohol) and internal factors (such as hormones or sleep disorders) contribute to activate this loaded anatomical substrate, resulting in the attack of migraine.

Acute confusional migraine: a variant not to be missed

A middle age woman who had frequent migraines was admitted with memory loss following severe unilateral headache, restlessness and confusion. Investigations including haematology, biochemistry, cerebrospinal fluid analysis serology and imaging were normal. As she had frequent migraines with a history of ophthalmoplegic migraine, acute confusional migraine was thought of as a possibility. The patient responded dramatically to intravenous sodium valproate. We report this case to emphasise that acute confusional migraine, a rare variant of migraine, is occasionally encountered in adults and prompt recognition will lead to appropriate management.

Acute confusional migraine: is it a distinct form of migraine?

The International Classification of Headache Disorders (ICHD-II) - 2004 recognises many migraine variants (different from migraine without aura and migraine with typical aura), but acute confusional migraine (ACM) remains unclassified and most clinicians are not well acquainted with it.

AIM

The aim of this study was to illustrate ACM in the neuropaediatric practice, to discuss its place in the ICHD-II and to propose diagnostic criteria.

PATIENTS AND METHODS

A total of 2509 files of newly diagnosed patients, aged 0-18 years, treated as in- and outpatients in the Neuropaediatric Ward at the Plovdiv Medical University Hospital between 2002 and 2006 were screened retrospectively. Their diagnosis was based on detailed medical history, physical and neurological examination, additional functional, imaging and laboratory investigations. Migraine and migraine variants were diagnosed according to ICHD-II, but specific forms (e.g. ACM and Alice in wonderland syndrome) were also included.

RESULTS

One hundred and eleven patients met the diagnostic criteria for migraine. Migraine variants comprised 24.3% of all migraine cases. In particular, ACM represented 11.1% of migraine variants or 2.7% of migraine and 0.12% of all paediatric neurological diseases. Here, we report three cases of ACM with analysis of the typical clinical and EEG features, review the literature and propose diagnostic criteria.

CONCLUSION

ACM may present as either the only manifestation of a migraine attack or in the context of other migraine forms. ACM should have its own distinct place in the ICHD-II, may be as a subtype of migraine with complex aura.

Emerging target-based paradigms to prevent and treat migraine

Migraine is a primary brain disorder resulting from altered modulation of normal sensory stimuli and trigeminal nerve dysfunction. The second edition of the International Classification of Headache Disorders (ICHD-2) defines seven subtypes of migraine. Migraine treatment can be acute or preventive. New targeted therapies include 5-HT(1F) receptor agonists, calcitonin gene-related peptide (CGRP) antagonists, nitric oxide synthetase inhibitors, and ion channel antagonists. A recent development is the creation of antibodies to CGRP and its receptor for migraine prevention.

Evaluation of diagnostic and prognostic value of clinical characteristics of migraine and tension type headache included in the diagnostic criteria for children and adolescents in International Classification of Headache Disorders--second edition

Data about the sensitivity and the specificity of the items included in the diagnostic criteria for migraine and tension type headache (TTH) in children is limited and sometimes controversial.

AIM

To evaluate the diagnostic value of characteristics of migraine and TTH included in the diagnostic criteria of ICHD-II and according to results to suggest additional criteria for diagnostic differentiation of primary paediatric headache.

PATIENTS AND METHODS

The investigation consisted of an epidemiological school-based study (1029 pupils completed the study and 412 had chronic or recurrent headache) and a clinical study conducted in Paediatric Neurology Ward and outpatient clinic (203 patients with chronic or recurrent headache). Inclusion criterion was at least two episodes of headache during the last year. Exclusion criteria were: headache occurring only during acute infections; withdrawal of informed consent. ICHD - II was used to classify headache. The diagnostic value of characteristics of migraine and TTH was measured using sensitivity, specificity, odds ratio and area under receiver operating characteristic curve (AUC).

RESULTS

Regarding the AUC, the best diagnostic items for migraine are: moderate or severe intensity or only severe intensity, pain aggravation by physical activity, pulsating quality, respectively, for TTH - no photophobia, no nausea, no aggravation by physical activity, mild or moderate intensity and non-pulsating quality. The most significant symptom for increasing the migraine risk was pulsating pain and the most significant items for TTH risk were no photophobia, bilateral location and no nausea. Family history of migraine also increased migraine risk and could be either included in the diagnostic criteria for migraine or recommended as additional item in differentiating migraine and TTH with overlapping diagnostic criteria. According to AUC, we could recommend changing the content of the item of intensity for migraine as only severe intensity.

A concise discussion of headache types, part 2: migraine

Nearly one in four United States households includes someone with migraine. However, because migraines are unpredictable and the symptoms vary and mirror those of other headache types and other illnesses, diagnosis is difficult, but not impossible. Literature lays claim to seven migraine types, some of which are discussed within this article, and although they have similar symptoms, some types have very unique symptoms. This article represents the first part of a discussion of migraine. The continuation of the discussion of migraine includes a discussion of migraine triggers and treatments, as well as compounded formulations for the treatment of migraine.

Defining the differences between episodic migraine and chronic migraine

Chronic migraine (CM) and episodic migraine (EM) are part of the spectrum of migraine disorders, but they are distinct clinical entities. Population-based studies have shown that those with CM demonstrate higher individual and societal burden because they are significantly more disabled than those with EM and have greater impaired quality of life both inside and outside the home. Proper diagnosis of both conditions requires clearly defined clinical criteria. Diagnosis enables the initiation of appropriate treatments and risk-factor modification, which ultimately improve functional status and quality of life for persons with migraine. Recognizing that both disorders are on the spectrum of migraine, this review serves as a guide to define the disease state of CM as distinct from EM in terms of clinical, epidemiological, sociodemographic, and comorbidity profiles.

Hormonal manipulation strategies in the management of menstrual migraine and other hormonally related headaches

Menstrual migraine and other hormonally related headaches are common in women. Falling estrogen levels or estrogen withdrawal after periods of sustained higher levels can trigger migraine. It makes sense to target this trigger for management of hormonally related headaches, particularly when nonhormonal strategies have been unsuccessful. Decision making regarding the use of hormonal contraception and menopausal hormone therapy is complex and commonly driven by other factors, but hormonal manipulation can potentially improve the course of migraine. Providers caring for migraineurs are appropriately concerned about stroke risk. Estrogen-containing hormonal contraceptives are relatively contraindicated for women who have migraine with aura. Postmenopausal hormone therapy is acceptable for women with a history of migraine. For these women, transdermal estradiol is recommended. Estrogen replacement is important for women who undergo an early menopause, whether natural or induced. Practical strategies for hormonal manipulation in the management of migraine and other hormonally related headaches are presented.

Management of Migraine Headaches

With 17% to 18% of women suffering from migraine headaches, clinicians will often be asked by their patients to prescribe medication. Migraine is an episodic chronic disease that is best managed with an overall treatment plan, rather than treated as an acute illness that is managed with sporadic medications. Realistic goals for the long-term management of migraine are based on patient education and an ongoing discussion between patient and provider. This article reviews the clinical presentation of migraine and recommendations for both acute and preventive treatment, including complementary therapies. "Red flags" that could be signs of more serious neurologic illness are presented. The management of migraine in pregnancy is also reviewed.