Archive for the ‘Migraine’ Category

Different pathophysiologic hypotheses have been proposed to explain these findings. Firstly, trigger substances might enter the systemic circulation through the right-to-left shunt instead of being trapped in the pulmonary capillaries. These trigger substances could induce cerebral vascular instability or increased excitability of the CNS and provoke migraine attacks. In individuals without a right-to-left shunt or after percutaneous closure, a larger amount of trigger substances is needed to induce migraine by overwhelming the filter capacity of the lungs. These trigger substances are proposed to be vasoactive chemicals such as serotonin or (micro) emboli. The latter might also explain the increased risk of ischemic stroke or transient ischemic attack in patients with migraine with aura. This increased risk might be explained by the elevated levels of platelet activation and platelet/leukocyte interaction in patients with migraine. The same interactions have been reported in the pathophysiology of ischemic stroke. Moreover, it has been shown that the incidence of subclinical brain infarction diagnosed with magnetic imaging is higher in patients with migraine with aura when compared to control sub-jects. As mentioned, the effect of shunt closure on the occurrence of migraine seemed to be more pronounced in patients who had migraine with aura. In support of this hypothesis, aura is accompanied by hypoperfusion of the occipital cortex, and emboli seem to have a predilection to embolize in this brain area. Consistent with this hypothesis is the finding that anticoagulant and high-dose antiplatelet therapy seems to decrease the incidence of migraine. comments
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The Relationship Between Migraine and Right-to-Left Shunt: Migraine CriteriaIn contrast, Yankovsky and Kuritzky reported aggravation of migraine with aura into a daily pattern after closure of an ASD in a single patient. The latter was also suggested by Mortelmans et al, who found an aggravation of migraine with aura after percutaneous ASD closure with relatively larger Amplatzer ASD devices. However, the reason for this observation remains unexplained. It is hypothesized that an increased nickel release from the closing device might induce cortical-spreading depressions. These depressions have been suggested to be associated with migraine with aura. However, Mortel-mans et al suggested that microthrombi formed on the left-sided disk during the endothelization process could embolize and provoke migraine attacks. Indeed, even macrothrombi seem not to be so uncommon after device closure. further
In almost all reports that describe the relationship between shunt closure and migraine, the diagnosis of migraine and migraine with aura was based on the International Headache Criteria, except for the report by Azarbal et al. In their study, the presence or absence of migraine was self-reported by patients on the basis of a diagnosis made by either their primary care physician or their neurologist. However, in this study the validated Migraine Disability Assessment Questionnaire was used to assess migraine severity.
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We and others> have described the changes in prevalence of migraine after percutaneous PFO closure. These data are summarized in Table 1. All studies, except for the study by Schw-erzmann et al, showed a significant reduction in the prevalence of migraine and migraine with aura after percutaneous PFO closure. The relative reduction in prevalence of migraine varied from 29 to 59%. For migraine with aura, the relative reduction in prevalence was even more pronounced and varied from 33 to 74%. purchase prozac online
Although Schwerzmann et al could not identify a significant decrease in prevalence of migraine, they found a reduction in the frequency of migraine attacks by 62% in patients with migraine without aura and 54% in those with migraine with aura. The major criticism of these studies was their retrospective and nonrandomized design. However, recently, Anzola et al reported a case-control study that showed a significant overall improvement of migraine after percutaneous PFO closure in comparison to medical treatment during a 1-year follow-up. This seems to be independent of migraine subtype and of previous cerebrovascular disease.
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The Relationship Between Migraine and Right-to-Left Shunt: Occurrence of Right-to-Left Shunt and MigraineIn patients with migraine, the prevalence of a right-to-left shunt seems to be higher when compared to the general population. Two investigational groups used transcranial Doppler ultrasound to determine right-to-left shunts in patients with migraine. A right-to-left shunt was found in 23% of the patients with migraine without aura. Forty-one to 48% of the patients with migraine with aura had a detectable right-to-left shunt. However, in only 16 to 20% of the control group could a detectable shunt be found. Similar findings were reported by Schwerzmann et al using transoesophageal echocardiography, who found that only PFOs with large shunts were found more often in patients with migraine with aura compared to control subjects. These observations suggest that migraine, particularly migraine with aura, may be associated with right-to-left shunting, especially in larger shunts. Link
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The most common origin of a right-to-left shunt is the patent foramen ovale (PFO). The PFO is an important feature of fetal circulation. The interatrial septum primum on the left side and the interatrial septum secundum on the right side maintain a central communication before birth, so that blood bypasses the pulmonary circulation. After birth, the pressure in the right atrium drops below the left atrial pressure, and this results into a functional closure. The latter may lead to fusion of the septum primum and secundum (anatomic closure). However, in 25% of the overall population, this fusion does not take place and the communication remains what is called probe patent, as it can open as a (one-way) valve when the right atrial pressure exceeds the left atrial pressure. This right-to-left shunt may be associated with paradoxical embolization of thrombi and has been postulated as a mechanism for cryptogenic stroke in young adults. Source
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The Relationship Between Migraine and Right-to-Left ShuntMigraine is a very common type of headache, affects the quality of life importantly, and has been ranked among the most disabling medical illnesses in the world. Migraine seems to be a complex disorder in which genetic, environmental, behavioral, and other as-yet unidentified factors interact to trigger the typical migraine attacks. A causal relationship between migraine and a right-to-left shunt has been proposed, particularly in patients with migraine with auraA However, the underlying pathophysiologic mechanism of this relationship is not well understood and remains hypothetical. In this review, we describe the relationship between both cardiac and pulmonary right-to-left shunts and the occurrence of migraine, and highlight observations that might support some pathophysiologic hypotheses of migraine. www.cheap-asthma-inhalers.com
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