EN
Lacunar infarcts have been defined as small lesions within a diameter of 1.5 centimeters causing mild symptoms. However, we treated a patient showing prolonged, severe disturbance of the cognitive function after a lacunar infarct. The 85-year–old woman was found lying on the floor of her house, and she was transported to our hospital. Computed tomography (CT) revealed a right lacunar infarct, and magnetic resonance imaging (MRI) showed severe periventricular hyperintensity (PVH) of her brain. Her severe consciousness disorder showed improvement, but severe cognitive impairment including disorientation remained when she was transferred to another hospital. These findings suggested that the reserve capacity of her brain was minimal. The addition of a lacunar infarct to a severe situation like this might induce severe cognitive impairment.