Prevalence and grade of RLS in migraine

Background: Right-to left shunt (RLS) is regarded as a risk factor resulting in migraine, but the relevance between the RLS and migraine remains controversial. This paper aims at investigating the prevalence and RLS grade of patent foramen ovale (PFO) in cases of migraine (including migraine with and without aura) and evaluate the relationship between PFO and migraine. Methods: Synchronous test of contrast transthoracic echocardiography and contrast transcranial Doppler ultrasonography was performed in 251 cases of migraine, which contains 62 cases of migraine with aura (MA) and 189 cases without aura (MO) and 275 healthy adults. Among these cases, 25 cases with migraine and 14 healthy adults were evaluated through transesophageal echocardiography. Results: (1). The prevalence of permanent RLS, total RLS, and large RLS in migraine was 11.16%, 39.04%, and 17.13%, respectively, which was significantly higher than that of the controls ( P  = .042, <.001, and.001, respectively). (2). Permanent RLS was detected as 7.93% of the cases in MO, 20.96% in MA, and 6.18% in controls. Total RLS was detected as 35.98% of the cases in MO, 48.38% in MA, and 23.64% in controls. Large RLS was detected as 13.76% of the cases in MO, 27.41% in MA, and 7.27% in controls. Compared with controls, the positive rate of total RLS and large RLS in MO increased ( P  = .004 and.022, respectively), the that of permanent RLS, total RLS, and large RLS in MA also increased ( P  < .001 for each of the comparisons). The positive rate of permanent RLS and large RLS in MA was remarkably higher than that in MO ( P  = .005 and.013, respectively). (3) The presence of large-size PFO (≥2.0 mm) of migraine showed higher than that of the controls ( P  = .048). Conclusions: PFO is associated with the migraine (especially with aura), when it is permanent RLS, large RLS, and large-size PFO (≥2.0 mm).