Page 19 - Migraine, the heart and the brain

What are the pathophysiological explanations for the association between RLS and 1 migraine?
One proposed mechanism was the transport through the RLS of venous blood
constituents which are normally not (or at decreased levels) present in the arterial
circulation. Such postulated constituents were venous (paradoxical) emboli and serotonin.44 In a mice study it was shown that small particulate or air emboli injected into the carotid artery were able to evoke a cortical spreading depression (CSD) without causing ischemia, hereby linking emboli to migraine aura.45 In a small open label study it was shown that 87% of migraine patients with RLS had a 50% or greater reduction in migraine frequency when using the emboli-preventing drug clopidogrel.46 In Chapter IV a review is given of different causes of embolic material and its ability to cause migraine aura attacks.
Non-shunting cardiac abnormalities
Patients who underwent pulmonary vein ablation, during or after this procedure had a new onset of migraine, or an increase of migraine attack frequency.47;48 During this procedure a catheter is placed in the left atrium and small scars are made locally. Emboli in the left (atrial) circulation, without the presence of a RLS, are thus associated with migraine in humans. Another example of a non-shunting disease is Marfan syndrome, a connective tissue disorder with aortic root dilatation as one of the major symptoms. In one study an association between Marfan syndrome and migraine with aura was reported.49 However, conflicting case reports have been published with both new onset but also cessation of migraine with aura after interventional procedures of the aortic root.50;51 We hypothesized that the presence of aortic root pathology in Marfan syndrome increases the prevalence of migraine. In Chapter V migraine prevalence in Marfan syndrome patients with and without aortic root pathology is described.
RLS and ischemic brain lesions
PFO, the most prevalent cause of RLS, has been associated with an increased risk of stroke in several studies in patients with stroke, speci cally in young patients.52;53 This however were studies not speci c in migraine patients. Furthermore in ischemic stroke patients aged <45 years of age, those with RLS had a higher risk also to have migraine with aura.54 Large population studies have shown that migraine with aura is associated with an increased risk for ischemic stroke (RLS status in subjects was not known).10
Introduction
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