Leukoencephalopathyを伴い皮質下出血を繰り返したCerebral amyloid angiopathyの一例

MULTIPLE HEMORRHAGIC CEREBRAL AMYLOID ANGIOPATHY ASSOCIATED WITH LEUKOENCEPHALOPATHY

　Binswanger病様のleukoencephalopathyを伴ない4回の皮質下出血を繰り返したcerebral amyloid angiopathyの一例を若干の文献的考察を加えて報告する。

　患者は78歳女性で以前から軽度の痴呆症状を認めた。昭和63年9月から平成元年4月までに4回の皮質下出血を繰り返し，高度の痴呆状態となった。出血性病変に加え両側の自質は，CTスキャンで低吸収域（灰白質とのCT値の差が14〜15HU），MRI T₂強調画像で高信号域として描出されBinswanger病のCT，MRI所見に類似した。脳皮質のバイオプシーの病理組織学的検査では皮質小動脈壁にアミロイドの沈着を認めたほか，著明なヒアリン化や内皮の増殖により閉塞性変化をきたした血管も認められた。これらの閉塞性病変が白質の慢性乏血をきたしBinswanger病様の白質病変，すなわらIeukoencephalopathyを招来したと考えられる。

The authors present a case of cerebral amyloid angiopathy (CAA) which caused multiple recurrent subcortical hemorrhages and leukoencephalopathy similar to Binswanger's disease. CT scan revealed bilateral hypodensity of the hemispheric white ma-tter in addition to multiple subcortical hemorrha-ges. The difference between white and gray mat-ter densities was 14~45 HU. T₂-weighted MRI showed the hemispheric white matter as high in-tensity. These findings on CT and MRI are com-patible with those observed in leukoencephalo-pathy like Binswanger's disease. A biopsy of the cortex was performed and histological examinationrevealed amyloid deposition in the aretrial wall. In addition to amyloid deposition, obliterative in-timal proliferation and hyaline degeneration of the vessel were observed. It is thought that the occlu-sive vascular change due to CAA may induce chro-nic hypoperfusion of the hemispheric white matterand cosequently the leukoencephalopathy may de-velop. In the aged population, CAA is notewor-thy as a cause of both hemorrhagic and ischemic lesions, because the incidence of CAA is increasing with age.