1,720,990 research outputs found
Migraine in women: the role of hormones and their impact on vascular diseases
No full text"Migraine is a predominantly female disorder. Menarche, menstruation, pregnancy, and menopause, and also the use of hormonal contraceptives and hormone replacement treatment may influence migraine occurrence. Migraine usually starts after menarche, occurs more frequently in the days just before or during menstruation, and ameliorates during pregnancy and menopause. Those variations are mediated by fluctuation of estrogen levels through their influence on cellular excitability or cerebral vasculature. Moreover, administration of exogenous hormones may cause worsening of migraine as may expose migrainous women to an increased risk of vascular disease. In fact, migraine with aura represents a risk factor for stroke, cardiac disease, and vascular mortality. Studies have shown that administration of combined oral contraceptives to migraineurs may further increase the risk for ischemic stroke. Consequently, in women suffering from migraine with aura caution should be deserved when prescribing combined oral contraceptives.
Conventional vascular risk factors: Their role in the association between migraine and cardiovascular diseases
No full textIntroduction: Migraine, in particular migraine with aura, has been found to be associated with cardiovascular disease. However, the role of conventional vascular risk factors in the association is still debated. The aim of the present review is to address the association between migraine and conventional cardiovascular risk factors as well as to address their
possible role in the association between migraine and cardiovascular disease.
Methods: Data for this review were obtained through searches in multiple sources up to May 2014 using the terms ‘‘migraine’’ OR ‘‘headache’’ in combination with all the vascular risk factors of interest.
Results: Data about the possible association between migraine and high blood pressure values are heterogeneous, hindering any final conclusion. Data addressing the possible association between migraine and diabetes mellitus indicate the lack of any association or in some cases a negative association between the two conditions. The body of evidence on
the role of dyslipidemia in migraineurs is relatively homogeneous and, with few exceptions, reports an association
between migraine and an unfavorable lipid profile; however, the difference in lipid levels between migraineurs and
non-migraineurs is small and its clinical implication unclear. Regarding obesity, a trend has been observed of increased risk of migraine with increasing obesity, especially in young patients, albeit in the midst of conflicting data. Evidence about
the association between cigarette smoking and migraine mostly indicates that migraineurs are more commonly smokers than non-migraineurs. On the other hand, the majority of the available studies report less alcohol use in migraineurs than
in non-migraineurs. Finally, many of the available studies suggest a more frequent family history of cardiovascular disease in migraineurs as compared to non-migraineurs. Since most of the studies that supported the association between
migraine and cardiovascular disease adjusted the analyses for the presence of several vascular risk factors, they cannot entirely explain this association.
Conclusions: Based on the available reported data, it seems unlikely that the higher risk of cardiovascular disease in migraineurs is mediated by any single vascular risk factor. For this reason the role of specific interactions among risk factors with the contribution of genetic, environmental, personality and psychological factors should be appropriately
investigated
Diagnostic criteria for CADASIL in the International Classification of Headache Disorders (ICHD-II): are they appropriate?
No full textWe reviewed the characteristics of headache in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), to verify the appropriateness of the International Classification of Headache Disorders, second edition (ICHD-II) criteria. Available data were found through Medline/PubMed using the keyword "cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)". The search was restricted to studies published in English in the years between 1993 and 2008. We excluded studies that did not report original data on CADASIL and information regarding the presence of headache. We found 34 studies reporting data on 749 patients overall; 387 (51.7%) patients had headache. According to the authors' definition, 356 (92%) patients were reported as having migraine and 31 (8%) as having headache. Of the 356 patients who were defined as migraineurs, 125 (35.1%) had migraine with aura, 7 (2%) migraine without aura, 156 (43.8%) unspecified migraine and 68 (19.1%) had more than one type of migraine. Among the 31 patients reported as suffering from headache, the headache was not further detailed in 18 (58.1%) patients; it was defined as chronic in 6 (19.3%), as resembling migraine with aura in 4 (12.9%), as resembling migraine without aura in 2 (6.5%) and as tension type in 1 (3.2%) patient. In patients with CADASIL, the headache was usually referred to as migraine and mostly as migraine with aura. However, this referral is formally incorrect since the diagnostic criteria for any type of migraine in the ICHD-II require that the disturbance is not attributed to another disorder. For this reason, we suggest updating the ICHD-II in relation to CADASIL. Our suggestion is to insert a new category referred to as Headache attributed to genetic disorder including Headache attributed to CADASIL
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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