Background.-Though symptomatic medication overuse is believed to play a major role in progression from episodic to chronic or transformed migraine (TM), population-based longitudinal data on these agents are limited.Objectives.-To assess the role of specific classes of acute medications in the development of TM in episodic migraine (EM) sufferers after adjusting for other risk factors for headache progression.Methods.-As a part of the American Migraine Prevalence and Prevention study (AMPP), we initially surveyed a population sample of 120,000 individuals to identify a sample of migraineurs to be followed annually over 5 years. Using logistic and linear regression, we modeled the probability Conclusion.-EM sufferers develop TM at the rate of 2.5% per year. Any use of barbiturates and opiates was associated with increased risk of TM after adjusting for covariates, while triptans were not. NSAIDs were protective or inducers depending on the headache frequency.

Objective-To develop and validate a questionnaire for assessing cutaneous allodynia (CA), and to estimate the prevalence and severity of CA in the migraine population. (n = 11,388) completed the Allodynia Symptom Checklist, assessing the frequency of allodynia symptoms during headache. Response options were never (0), rarely (0), less than 50% of the time (1), ≥50% of the time (2), and none (0). We used item response theory to explore how well each item discriminated CA. The relations of CA to headache features were examined. Methods-MigraineursResults-All 12 questions had excellent item properties. The greatest discrimination occurred with CA during "taking a shower" (discrimination = 2.54), wearing a necklace (2.39) or ring (2.31), and exposure to heat (2.1) or cold (2.0). The factor analysis demonstrated three factors: thermal, mechanical static, and mechanical dynamic. Based on the psychometrics, we developed a scale distinguishing no CA (scores 0-2), mild (3-5), moderate (6-8), and severe (≥9). The prevalence of allodynia among migraineurs was 63.2%. Severe CA occurred in 20.4% of migraineurs. CA was associated with migraine defining features (eg, unilateral pain: odds ratio, 2.3; 95% confidence interval, 2.0 -2.4; throbbing pain: odds ratio, 2.3; 95% confidence interval, 2.1-2.6; nausea: odds ratio, 2.3; 95% confidence interval, 2.1-2.6), as well as illness duration, attack frequency, and disability.Interpretation-The Allodynia Symptom Checklist measures overall allodynia and subtypes. CA affects 63% of migraineurs in the population and is associated with frequency, severity, disability, and associated symptoms of migraine. CA maps onto migraine biology. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptCutaneous allodynia (CA) is characterized by pain provoked by stimulation of the skin that would ordinarily not produce pain. 1 The underlying mechanism of facial CA is sensitization of the nociceptive neurons in the trigeminal nucleus caudalis, which receives convergent afferent input from the dura mater and periorbital skin. 2,3 Clinic-based studies suggest that about two thirds of migraine sufferers experience development of CA. [4][5][6] As a marker of central sensitization, allodynia has been proposed as a risk factor for progression to chronic migraine. 7-9 Therefore, CA has significant implications for our understanding of the pathophysiology of migraine attacks, for the implementation of treatment, and for assessing prognosis.CA is usually assessed by quantitative sensory testing (QST). QST requires specialized equipment, training, and testing; it is too cumbersome and costly for wide-spread use in clinical practice or epidemiological research and is subject to temporal sampling error. As a consequence, most studies on headache and CA come from a small number of headache centers and the highly selected patients treated there. 5,10,11 There is an urgent need to develop and validate simple methods for assessing CA to better characterize CA in representative samples and...

Objective To characterise and compare the sociodemographic profiles and the frequency of common comorbidities for adults with chronic migraine (CM) and episodic migraine (EM) in a large population-based sample. Methods The American Migraine Prevalence and Prevention (AMPP) study is a longitudinal, population-based, survey. Data from the 2005 survey were analysed to assess differences in sociodemographic profiles and rates of common comorbidities between two groups of respondents: CM (ICHD-2 defined migraine; $15 days of headache per month) and EM (ICHD-2 defined migraine; 0e14 days of headache per month). Categories of comorbid conditions included psychiatric, respiratory, cardiovascular, pain and 'other' such as obesity and diabetes. Results Of 24 000 headache sufferers surveyed in 2005, 655 respondents had CM, and 11 249 respondents had EM. Compared with EM, respondents with CM had stastically significant lower levels of household income, were less likely to be employed full time and were more likely to be occupationally disabled. Those with CM were approximately twice as likely to have depression, anxiety and chronic pain. Respiratory disorders including asthma, bronchitis and chronic obstructive pulmonary disease, and cardiac risk factors including hypertension, diabetes, high cholesterol and obesity, were also significantly more likely to be reported by those with CM. Discussion Sociodemographic and comorbidity profiles of the CM population differ from the EM population on multiple dimensions, suggesting that CM and EM differ in important ways other than headache frequency.

Chronic migraine (CM) is more disabling than episodic migraine in the population. Although most individuals with CM sought medical care for this disorder, the majority did not receive specific acute or preventive medications.

In the US population, the prevalence of CM was nearly 1%. In adjusted models, CM prevalence was highest among females, in mid-life, and in households with the lowest annual income. Severe headache-related disability was more common among persons with CM and most common among females with CM.

Objective: The authors estimated the prevalence and severity of cutaneous allodynia (CA) in individuals with primary headaches from the general population. Methods:We mailed questionnaires to a random sample of 24,000 headache sufferers previously identified from the population. The questionnaire included the validated Allodynia Symptom Checklist (ASC) as well as measures of headache features, disability, and comorbidities. We modeled allodynia as an outcome using headache diagnosis, frequency and severity of headaches, and disability as predictor variables in logistic regression. Covariates included demographic variables, comorbidities, use of preventive medication, and use of opioids.Results: Complete surveys were returned by 16,573 individuals. The prevalence of CA of any severity (ASC score ≥3) varied with headache type. Prevalence was significantly higher in transformed migraine (TM, 68.3%) than in episodic migraine (63.2%, p < 0.01) and significantly elevated in both of these groups compared with probable migraine (42.6%), other chronic daily headaches (36.8%), and severe episodic tension-type headache (36.7%). The prevalence of severe CA (ASC score ≥9) was also highest in TM (28.5%) followed by migraine (20.4%), probable migraine (12.3%), other chronic daily headaches (6.2%), and severe episodic tension-type headache (5.1%). In the migraine and TM groups, prevalence of CA was higher in women and increased with disability score. Among migraineurs, CA increased with headache frequency and body mass index. In all groups, ASC scores were higher in individuals with major depression. Conclusions:Cutaneous allodynia (CA) is more common and more severe in transformed migraine and migraine than in other primary headaches. Among migraineurs, CA is associated with female sex, headache frequency, increased body mass index, disability, and depression.Central sensitization, an increased excitability of spinal and medullary dorsal horn neurons resulting from ongoing input from C-fiber nociceptors, may lead to cutaneous allodynia (CA), a neurologic condition characterized by pain elicited by ordinary nonnociceptive stimulation of the skin. 1,2 During migraine, facial CA is likely to be a clinical manifestation of sensitization at the level of the trigeminal nucleus caudalis. 3,4 In clinic-based studies, most migraineurs develop CA during the course of an attack. 5-8 In migraine, CA has been proposed as a predictor of poor response to triptan therapy 8 as well as a risk factor for disease progression. 9Address correspondence and reprint requests to Dr. Marcelo E. Bigal, Global Director, Scientific Affairs, Neuroscience, One Merck Drive, P.O. Box 100, Whitehouse Station, NJ 08889-0100 Marcelo_Bigal@merck.com. * Members of the AMPP Advisory Group are listed in the appendix. Here, we used the ASC-12 to assess the prevalence and severity of CA in subjects with various types of primary headaches in the general population. Because CA has been recently suggested as a risk factor for migraine progression, we hypothesized ...

Background.-The strikingly higher prevalence of migraine in females compared with males is one of the hallmarks of migraine. A large global body of evidence exists on the sex differences in the prevalence of migraine with female to male ratios ranging from 2 : 1 to 3 : 1 and peaking in midlife. Some data are available on sex differences in associated symptoms, headache-related disability and impairment, and healthcare resource utilization in migraine. Few data are available on corresponding sex differences in probable migraine (PM) and other severe headache (ie, nonmigraine-spectrum severe headache). Gaining a clear understanding of sex differences in a range of severe headache disorders may help differentiate the range of headache types. Herein, we compare sexes on prevalence and a range of clinical variables for migraine, PM, and other severe headache in a large sample from the US population.Methods.-This study analyzed data from the 2004 American Migraine Prevalence and Prevention Study. Total and demographic-stratified sex-specific, prevalence estimates of headache subtypes (migraine, PM, and other severe headache) are reported. Log-binomial models are used to calculate sex-specific adjusted prevalence ratios and 95% confidence intervals for each across demographic strata. A smoothed sex prevalence ratio (female to male) figure is presented for migraine and PM.Results.-One hundred sixty-two thousand seven hundred fifty-six individuals aged 12 and older responded to the 2004 American Migraine Prevalence and Prevention Study survey (64.9% response rate). Twenty-eight thousand two hundred sixty-one (17.4%) reported "severe headache" in the preceding year (23.5% of females and 10.6% of males), 11.8% met International Classification of Headache Disorders-2 criteria for migraine (17.3% of females and 5.7% of males), 4.6% met criteria for PM (5.3% of females and 3.9% of males), and 1.0% were categorized with other severe headache (0.9% of females and 1.0% of males). Sex differences were observed in the prevalence of migraine and PM, but not for other severe headache. Adjusted female to male prevalence ratios ranged from 1.48 to 3.25 across the lifetime for migraine and from 1.22 to 1.53 for PM. Sex differences were also observed in associated symptomology, aura, headache-related disability, healthcare resource utilization, and diagnosis for migraine and PM. Despite higher rates of migraine diagnosis by a healthcare professional, females with migraine were less likely than males to be using preventive pharmacologic treatment for headache.Conclusions.-In this large, US population sample, both migraine and PM were more common among females, but a sex difference was not observed in the prevalence of other severe headache. The sex difference in migraine and PM held true across age and for most other sociodemographic variables with the exception of race for PM. Females with migraine and PM had higher rates of most migraine symptoms, aura, greater associated impairment, and higher healthcare resource utilization than

BackgroundLongitudinal migraine studies have rarely assessed headache frequency and disability variation over a year.MethodsThe Chronic Migraine Epidemiology and Outcomes (CaMEO) Study is a cross-sectional and longitudinal Internet study designed to characterize the course of episodic migraine (EM) and chronic migraine (CM). Participants were recruited from a Web-panel using quota sampling in an attempt to obtain a sample demographically similar to the US population. Participants who passed the screener were assessed every three months with the Core (baseline, six, and 12 months) and Snapshot (months three and nine) modules, which assessed headache frequency, headache-related disability, treatments, and treatment satisfaction. The Core also assessed resource use, health-related quality of life, and other features. One-time cross-sectional modules measured family burden, barriers to medical care, and comorbidities/endophenotypes.ResultsOf 489,537 invitees, we obtained 58,418 (11.9%) usable returns including 16,789 individuals who met ICHD-3 beta migraine criteria (EM (<15 headache days/mo): n = 15,313 (91.2%); CM (≥15 headache days/mo): n = 1476 (8.8%)). At baseline, all qualified respondents (n = 16,789) completed the Screener, Core, and Barriers to Care modules. Subsequent modules showed some attrition (Comorbidities/Endophenotypes, n = 12,810; Family Burden (Proband), n = 13,064; Family Burden (Partner), n = 4022; Family Burden (Child), n = 2140; Snapshot (three months), n = 9741; Core (six months), n = 7517; Snapshot (nine months), n = 6362; Core (12 months), n = 5915). A total of 3513 respondents (21.0%) completed all modules, and 3626 (EM: n = 3303 (21.6%); CM: n = 323 (21.9%)) completed all longitudinal assessments.ConclusionsThe CaMEO Study provides cross-sectional and longitudinal data that will contribute to our understanding of the course of migraine over one year and quantify variations in headache frequency, headache-related disability, comorbidities, treatments, and familial impact.