Localization of Infratentorial Lesion could Predict Patent Foramen Ovale as an Etiology in Embolic Stroke of Undetermined Source

Aim: Embolic stroke of undetermined source (ESUS) is a clinical construct introduced to describe cryptogenic stroke cases with ambiguous diagnoses. Cardiac causes are recognized as a major cause of ESUS, Patent foramen ovale (PFO) being among them. We aimed to investigate the relationship between infarct patterns and PFO in patients with ESUS.Methods: We evaluated 190 consecutive patients with ESUS registered in the Tokyo Women’s Medical University Stroke Registry. Among them, 94 patients who underwent magnetic resonance imaging and angiography, as well as transthoracic and transesophageal echocardiography, were included in this study. The infarct patterns were classified according to location (infratentorial or non-infratentorial lesions), size (small or large infarcts), and number (single or multiple lesions).Results: Prevalence of PFO was significantly higher in patients in the infratentorial than those in the non-infratentorial lesion group (40.7% versus 14.9%, respectively; P=0.007). However, neither lesion size nor number were associated with PFO. In multivariate logistic regression analysis, the presence of infratentorial lesions was independently associated with PFO in ESUS patients (odds ratio: 2.18; 95% confidence interval: 1.24-3.95; P＜0.007). In 21 patients with PFO, large PFOs were more prevalent in the infratentorial than in the non-infratentorial lesion group. Conclusions: Infratentorial lesions may be independently associated with PFO in patients with ESUS. The presence of infratentorial lesions could predict the presence of PFO in ESUS cases.