左視床前内側部の出血により生じた健忘症候群の1例

A case of amnesic syndrome caused by hematoma in the left anterior medial thalamus

I．はじめに

　健忘を中核とする病態は健忘症候群と呼ばれる．これは意識障害がなく，全般的な知的機能は保たれるが，前向きおよび後向きの記憶障害を呈するもので，その原因として脳血管障害，頭部外傷，脳腫瘍，脳炎，変性疾患，感染症，膠原病，痴呆性疾患，代謝障害，アルコール中毒，低酸素脳症などがある^1）．健忘症候群が限局性病変で発現する場合には，脳血管障害^2-4）によるものが最も多く，脳梗塞が一般的であるが，脳出血の報告は少ない^5-7）．今回，われわれは左視床に限局した出血巣で健忘症候群を呈した1例を経験したので報告する．

We reported a case of amnestic syndrome caused by a hematoma in the left thalamus. The case was that of a 68-year-old, right-handed man who suddenly showed amnestic syndrome. He had neither motor paresis nor sensory disturbance. Clinical examination showed he had disorientation, anterograde amnesia and mild re-trograde amnesia. Immediate recall and remote memory were intact, but recent memory was severely impaired. CT scan revealed a high density area in the anterior medial part of the left thalamus.

We concluded that amnesia in this patient was caused by fasciculus mamillothalamicus damage be-cause of a hematoma during thalamic hemorrhage.