Mechanism of medullary infarction based on arterial territory involvement

Abstract

Background and Purposes: The blood supply to the medulla oblongata is distinct from the other areas of the brainstem. Therefore, the mechanism of medullary infarctions may be distinct. However, few studies have addressed the mechanism of medullary infarctions.Methods: Of 3833 stroke patients that were on the stroke registry from February 1999 until April 2008, patients with medullary infarctions that were demonstrated on diffusion-weighted MRI, were enrolled. We analyzed the topography of the lesions, arterial territories involved, and etiologic mechanisms, particularly in relation to arterial territories involved.Results: A total of 142 patients were enrolled. Bilateral medullary infarctions were rare (2.2%). Lesions involving the anteromedial or lateral territories were common in the upper medulla oblongata, whereas lateral territorial involvements were common in the middle and lower medulla oblongata. Significant stenosis (>50%) or occlusion of the verterbral artery was common (52.2%). Among stroke subtypes, large artery atherosclerosis was most common (34.5%), whereas lacunae and cardioembolism were rare (3.5%, 4.2%, respectively). Vertebral artery dissection was frequent. Stroke mechanisms were different among the vascular territories involved. Large artery atherosclerosis produced a lesion in the lateral, anteromedial, and posterior territories. None of the cardioembolism or other etiologies involved anteromedial or anterolateral territory, but all involved the lateral and/or posterior territories. Lacunar infarction was only found in the anteromedial and the anterolateral territory.Conclusions: The topography and mechanisms of infarctions involving the medulla oblongata were different among the involved arterial territories. These findings may be associated with the distinct arterial supplying pattern of the medulla oblongata.