特発性ウイリス動脈輪閉塞症の脳循環動態（第1報）—電気生理学的所見と神経放射線学的所見の対比検討

Cerebral Blood Flow Dynamics of Spontaneous Occlusion of the Circle of Willis (Part 1):Comparison between electrophysiological findings and neuroradiological findings

I．はじめに

　特発性ウイリス動脈輪閉塞症の小児2例，成人2例のSTA-MCA吻合術前後に，at restおよび過呼吸後の脳波（小児例）および体性感覚誘発電位（SEP）を記録した．それらの所見と，脳血管写上のウイリス動脈輪後半部の血行動態，およびCTscan上のlow density lesionとの関連を検討した上で，本症に対するbypass術の手術適応に対し考察を加えた．さらに本症の小児例に特徴的といわれる脳波のrebuild up^7,8）をSEP所見と関連づけて検討した．

Four cases (2 children and 2 adults) of spontaneous occlusion of the circle of Willis were studied using EEG, somatosensory evoked potential (SEP), cerebral angiography and CT scan.

The following results were obtained.

1) Among the above described parameters, SEP was the most useful to detect the ischemic change inthe thalamus when the obstruction of the posterior part of the circle of Willis extends, even before a low density lesion of the thalamus appears on CT.

2) In child cases, a decrease in the amplitude N₃ of SEP was observed after hyperventilation.