Migraine, patent foramen ovale and migraine triggers.

Little information exists about a causal association between PFO and migraine. Some patients identify Valsalva-provoking activities (VPA) as migraine triggers. Therefore, we speculate about a pathogenic connection. The object of the study is to investigate the prevalence of right-to-left shunt (RLS) in a cohort of patients suffering migraine with aura (MA) and its possible association with migraine attacks triggered by VPA. We investigated the circumstances triggering the migraine attacks, in a consecutive series of 72 MA patients and in a series of migraine without aura age and gender-matched. The presence and extent of RLS was assessed by transcranial Doppler. Massive RLS appeared in 38.9% of MA and in 6.5% of migraine without aura (p<0.001). MA patients identified at least one VPA as headache trigger in 45.8%. A trend was found between these triggering activities and massive RLS, both in MA group OR 2.7 [1.02-7.17] and in all migraine patients OR 2.5 [1.01-6.11]. According to our results, patients with migraine who have larger RLS tend to recognize activities that increase the extent of the shunt as a trigger of their migraine attacks.