Mechanism in progressive lacunar infarction - A case report with magnetic resonance imaging

Background: The mechanism of a progressive lacunar infarction is not well u nderstood, and changes in ischemic tissue after onset have not yet been cla rified clinically. Objective: To investigate the pathophysiological characteristics of a case of progressive lacunar infarction using diffusion-weighted and conventional magnetic resonance imaging (MRI) scans. Patient: A 73-year-old woman was hospitalized 18 hours after stroke onset a nd was diagnosed as having a lacunar infarction in the perforating territor y of the left middle cerebral artery. Despite treatment, the hemiparesis wo rsened, with the peak on the fourth day after onset. Diffusion-weighted and conventional MRI scans provided clues to the pathogenesis. Findings and Conclusions: In the acute stage, gradual enlargement of the hy perintense lesion, reflecting fresh ischemic tissue, and neurological deter ioration were observed by serial examination of diffusion-weighted MRI scan s. A conventional coronal MRI scan revealed a 2-layered ischemic lesion, su ggesting the involvement of perforating arteries. These findings indicated that hemodynamic impairment of the microcirculation in the perforators was the major cause of the lacunar infarction.