Abstract

Background
and Objectives: Migraine headaches are common in the general population with signi- ficant morbidity. Migraine, especially with aura is known to increase relative risk of ischemic stroke although the stroke mechanism is unclear. Recent data shows a high prevalence of patent foramen ovale(PFO) in migraine patients and PFO is known to be associated with cryptogenic stroke in young patients. In some studies, migraine headaches were relieved by PFO closure, and randomized controlled trial for that is ongoing. Transcranial Doppler(TCD) study is noninvasive tool and easily available test for detection of right to left shunt. By TCD study, we aimed to investigate the prevalence of PFO in migraine patients and to find the specific subgroup associated with the presence of PFO in Korean. Methods: From February 23, 2005 to April 25, 2005, we prospectively included the patients who had migraine diagnosed by international headache society(IHS) criteria. The clinical features including frequency, and aura were obtained. Headache frequency was divided to low(1 or less per month), moderate(2 to 7), high(8 or more). PFO was assessed with TCD with IV injection of agitated saline. The degree of right to left shunt was divided grade I when the embolic track was 5 or less, grade II when 6 to 15, grade III when above 16. Results: Among 38 patients included, 22(57.9%) patients showed positive results for PFO test by TCD. The most common degree of PFO was grade I(12), followed by Gr II(6), Gr III(4). The prevalence of PFO was not significantly different according to the presence of aura and severity of headache; PFO was positive in the 13/20(65%) of migraine with aura and in the 9/18(50%) of migraine without aura. Frequent headache(>8 per months) was more common in the patients with PFO(38.9%) than in patients without PFO(23.1%). Conclusions: In Korea, more than half of migraine patients were identified to have PFO in TCD study, while the prevalence of PFO in general population has been known as 15～25%. The PFO was more prevalent in patients with higher frequency, although it is not statistically signficant. These findings may suggest that the presence of PFO contributes development and manifestation of migraine.