内頸動脈閉塞症例における133Xe静注法による脳血流の検討

EVALUATIONS OF REGIONAL CEREBRAL BLOOD FLOW (RCBF) BY 133XENON IV METHOD IN PATIENTS WITH OCCLUSIONS OF BILATERAL INTERNAL CAROTID ARTERIES

　抄録　両側内頸脈の高度の狭窄又は閉塞を示す5症例（男4名，女1名，平均年齢57.4歳）において，予後と脳循環動態との関連を検討した。¹³³Xe静注法による脳血流の測定を行ない，正常成人における局所の平均値から−2SD以下の低い値を示す局所を脳血流低下と判定した。F meanでは4例が両側全汎減少型、1例が両側部分減少型を示したが予後に関し特異的な関連はみられなかった。一方Fgでは3例に部分減少型，2例に両側又は片側の全汎滅少型を認めた。Fg値で部分減少型を示した3例は神経学的にも症状は安定していた。しかし全汎減少型を示した2例とも突然死亡した。F meanとFgの両者でその評価を行なったが，Fgによる方が予後とより一致する結果を得た。本症例群ではFg値で評価すると全汎減少型を示す症例の予後は不良であり，注意深いfollow-upが必要と考えられた。

The studies of changes in regional blood flow (rCBF) have been reported on different clinical courses in the five cases (mean 57.4 y. o.) showing bilateral occlusion or stenosis of internal carotid arteries.

Values of rCBF using Fg (fast component in gray matter) were closely correlated with their clinical courses.

The three patients (2 males and 1 female) showed bilateral focal decreased patterns of rCBF and their uneventful clinical courses except for mild attacks of transient cerebral ischemia. However, the rest two male patients showed bilateral decreased pat-tern of rCBF and moderate hemiparesis including attacks of loss of consciousness. The one died suddenly because of the thalamic hemorrage and the other died also suddenly from the unknown etiology.

Such differences between the classification of clinical course and hemodynamics evaluated by r CBF was discriminated more clearly by Fg (fast component in gray matter) than by F mean (mean r CBF).

The authors concluded that the evaluation by Fg may be valuable to estimate prognosis of patients with bilateral occlusion of internal carotid artery. There are two patterns of decreased rCBF in our study. The patients with bilateral diffuse decreased patterns of rCBF should be followed up more carefully because of the sudden death from cerebral hemorrhage.