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.