[A case of amnesic stroke caused by left hippocampal infarction].

A 78-year-old woman was admitted to our hospital because of acute onset amnesia in March 1991. Neurological examination revealed right homonymous hemianopsia and clumsiness of the right hand. Magnetic resonance imaging (MRI) demonstrated abnormal intensity areas in the left hippocampus, parahippocampal gyrus, fimbria of the hippocampus and the occipital lobe. Immediate memory and long-term memory were relatively well-preserved, but short-term memory was severely disturbed. Her memory disturbance persisted for more than 9 months and she eventually developed an "amnesic stroke". According to the MRI findings, the "amnesic stroke" was produced by infarction of the left hippocampus, parahippocampal gyrus and fimbria of the hippocampus. We emphasized that in this case an "amnesic stroke" was caused by infarction of the left hippocampal lesions.