Pathogenic mechanism in patients with pure midbrain infarction

Abstract

Objective: The aim of this study was to investigate the frequency of pure midbrain infarction, vascular territories, neurological findings, symptom onset, stroke subtype, and embolic source.Methods: We retrospectively enrolled patients who were admitted to our stroke center from April 2006 to August 2012 within 7 days. We investigated the frequency of pure midbrain infarction, vascular territories, neurological findings, stroke subtype, stroke subtype, and embolic source. The vascular territories were classified into median zone (MZ), anterolateral zone (AZ), lateral zone (LZ), and dorsal zone (DZ).Results: Nine patients (3%) were diagnosed as having pure midbrain infarction (mean age: 74 years, 6 males). Vascular territories were MZ in 5 patients, AZ in 3 patients, and LZ combined DZ in 1 patient. Stroke subtypes were undetermined etiology in 5 patients, cardioembolism in 3 patients, and other etiology in 1 patient. Eye movement disorders and ataxia in MZ, hemiparesis in AZ were prominent neurological findings. Embolic sources were found in 6 patients, atrial fibrillation in 2 patients, patent foramen ovale in 2 patients, aortic atheromatous disease in 1 patient, and patent foramen ovale and aortic atheromatous disease in 1 patient.Conclusion: Pure midbrain infarction is very rare, and half of them had embolic sources. Therefore, when we see pure midbrain infarction, a diagnostic workup including transesophageal echocardiography should be performed to detect embolic source.