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: 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 ...

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Objective: To evaluate the association between migraine without aura (MO) and migraine with aura (MA) and 3 types of structural brain abnormalities detected by MRI: white matter abnormalities (WMAs), infarct-like lesions (ILLs), and volumetric changes in gray and white matter (GM, WM) regions.Methods: PubMed as well as the reference lists of identified studies and reviews were used to identify potentially eligible studies through January 2013. Candidate studies were reviewed and eligible studies were abstracted. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated for WMAs and ILLs.Results: Six population-based and 13 clinic-based studies were identified. The studies suggested that structural brain changes, including WMAs, silent ILLs, and volumetric changes in GM and WM regions, were more common in migraineurs than in control groups. The results were strongest for MA. The meta-analysis of WMAs showed an association for MA (OR 1.68; 95% CI 1.07-2.65; p 5 0.03) but not for MO (OR 1.34; 95% CI 0.96-1.87; p 5 0.08). The association of ILLs was greater for MA (OR 1.44; 95% CI 1.02-2.03; p 5 0.04) than for MO, but no association was found for MA (p 5 0.52) and MO (p 5 0.08) compared to controls. Conclusion:These data suggest that migraine may be a risk factor for structural changes in the brain. Additional longitudinal studies are needed to determine the differential influence of migraine without and with aura, to better characterize the effects of attack frequency, and to assess longitudinal changes in brain structure and function. Neurology â 2013;81:1260-1268 GLOSSARY ACC 5 anterior cingulate cortex; CAMERA 5 Cerebral Abnormalities in Migraine, an Epidemiological Risk Analysis; CI 5 confidence interval; DTI 5 diffusion tensor imaging; GM 5 gray matter; ICHD 5 International Classification of Headache Disorders; IHL 5 infratentorial hyperintense lesion; ILL 5 infarct-like lesion; MA 5 migraine with aura; MO 5 migraine without aura; OR 5 odds ratio; PAG 5 periaqueductal gray; VBM 5 voxel-based morphometry; WM 5 white matter; WMA 5 white matter abnormality.