左海馬の萎縮により言語性の近時記憶障害をきたした悪性グリオーマの1例

A Case of Malignant Glioma Associated with Verbal Recent Memory Disturbance due to Left Hippocampal Atrophy; Case report

I．はじめに

　記憶機能における海馬の役割については，1950年代の後半より臨床ならびに基礎の両面から詳細な研究がなされてきた．その結果，左側の海馬は言語性の近時記憶に，右側の海馬は非言語性の近時記憶に関与することが明らかになってきた．最近われわれは，悪性グリオーマに左海馬の萎縮を合併し，臨床的に言語性の近時記憶障害を呈した稀な症例を経験したので報告する．

Verbal recent memory disturbance was observed in a patient with a malignant glioma associated with left hippocampal atrophy. A 25 year-old male was admitted because of seizures. CT scan and MRI showed en-hanced mass lesions in the left temporal lobe associated with ipsilateral hippocampal atrophy. Neurological ex-amination disclosed right homonymous hemianopsia, word amnesia, alexia, agraphia and acalculia. Neuro-psychological examination disclosed verbal recent mem-ory disturbance, which consisted of impaired recall of the precisely memorized words after some interruption. Although hippocampal lesions are known to be often associated with cerebrovascular disease, hippocampal atrophy due to brain tumor is quite unusual. This case suggested that the left hippocampus is closely related to verbal recent memory. Hippocampal atrophy in this case conceivably derived from the decreased arterial flow due to perifocal edema or obstructive hy-drocephalus.