星状神経節遮断の頸動脈血流に及ぼす影響—特に中枢神経系循環と関連して

EFFECT OF STELLATE GANGLION BLOCK UPON CAROTID BLOOD FLOW AND ITS RELATION TO CEREBRAL CIRCULATION

Ｉ．緒言

　最近の研究によつて明らかにされた脳循環の特徴は，その複雑さにある^4）といわれるほどに脳循環を規定すると目される因子は多く，一律に論ずることは困難である。しかし，近年の研究が従来不完全であつた部分を徐々に補い，全体を解明しつつあることも事実である。

　かつて，てんかん，偏頭痛，脳卒中の症状の原因として脳循環不全があげられ^{11）12）17）}，現在もくも膜下出血時の脳血管攣縮とそれによる脳循環不全の重要性が強調されている^16）。近藤^19）はいわゆる"鞭打ち症"とよばれているものを頸部交感神経系の緊張異常がその因であるとし，外傷性頸性頭痛Migrain cervicale traumatiqueとよんでいるが，筆者は臨床的考察よりこの外傷性頸性頭痛症候群の症状の多くが頸部交感神経系のcentripetalおよびcentrifugal dysregulationのための中枢神経系循環不全によるものであり，この治療は星状神経節遮断Stellate ganglion block （以下SGBと略す）療法によるべきであると主張した^4）。

The effects of stellate ganglion block upon com-mon carotid and vertebral blood flow were studied in 22 mongrel dogs using noncannulating electro-magnetic flowmeter. Common carotid and vertebral artery flow increased after stellate ganglion block in all but two animals. Blood chemical factors such as pCO₂, checked before and after stellate ganglion block in the femoral artery and the external jugular vein, were shown to have no special effects on blood flow increase after stellate ganglion block. This increase was neither a passive one due to systemic blood pressure changes, for it occurred without rise, or with an actual fall in blood pressure.

Internal carotid artery flow was measured in two patients utilizing also a noncannulating electo-magnetic flowmeter. The flow before stellate gan-glion block was 378 ml and 390 ml/min. After stel-late ganglion block the flow increased up to 400mland 460 ml/min respectively, and did not show an inclination to decrease during 10 minute observa-tion.

The rate of increase of internal carotid blood flow in these two cases were 12% and were noted to have much similarity with 12.8% increase of common carotid blood flow in 20 mongrel dogs.

Although it is now generally conceded that cir-culation of the brain is different from other parts of the body in its defect of vasomotor control, the author could detect a definite increase after stellateganglion block in this experiment and the reasons were discussed from several points.

There is good evidence that the cerebral vessels contract on stimulation of the cervical sympathetic nerve. It seems justified that the cerebral blood vessels of man have sympathetic control, and block-ing the cervical sympathetic chain by a procaine injection causes an increase in blood flow of the cerebrum in certain pathological instances that might result from reflex vascular spasm.