[Memory disturbance caused by medial temporal lesion]

The memory disturbance caused by medial temporal lesion is reported concerning 6 cases of cerebral hemorrhage, infarction, brain tumor, and contusion. The memory disturbance was significant compared with the patient's intact orientation and normal intelligence. In the category of memory, recent memory was more markedly disturbed than the immediate or remote memory. From the viewpoint of the lesion, the memory disturbance was more severe when, in addition to the hippocampus, the entorhinal gyrus or amygdala was damaged. The visual memory disturbance was mild and no difference was observed in the verbal or visual memory according to whether the lesion was right or left. The memory disturbance was usually transient and marked improvement was observed in some cases.