実験的急性交通性水頭症における髄液圧および脳組織圧動態

MEASUREMENT OF VENTRICULAR FLUID PRESSURE AND BRAIN TISSUE PRESSURE IN ACUTE EXPERIMENTAL COMMUNICATING HYDROCEPHALUS

I．はじめに

　脳出血・頭部外傷等に続発する急性水頭症は単に髄液の循環障害や頭蓋内圧亢進にとどまらず，種々の神経損傷を生じるためその病態は臨床上重要な問題をふくんでいる。髄液吸収障害時の圧動態は病態形成上重要な役割をなすと考えられるが，これまでは単に髄液圧との関連で述べられた^1,14）のみであり，頭蓋内システムにおける圧分布との関連で検討した報告はみられない。近年行なわれるようになつてきた脳組織圧測定^6,10）は，その病態解明上ひとつの手がかりを与えていると考えられる。

　著者らはCarbon black浮游液を猫の脳室内に注入することによつて，実験的に作成した急性交通性水頭症の進行過程で髄液圧および脳組織圧をそれぞれ測定するとともに，大脳白質水分含有量の変化，脳血流の変化について観察し，水頭症形成機序について検討を加えた。

Malabsorption of cerebrospinal fluid was made experimentally by the administration of small amount of neutral carbon black suspension into the lateral ventricles of 22 adult cats. The com-partmental analysis of intracranial pressure at the intraventricular fluid and tissue pressure in the cerebral white matter was carried out in the early stage of the communicating hydrocephalus.

Following results were obtained:

1) Cerebrospinal fluid pressure from the lateral ventricle was always significantly higher than that from the brain tissue during the process of ven-tricular expansion.

2) Water content in the cerebral white matter was correspondingly increased when the pressure difference with greater value in ventricular fluid pressure was maintained. However tissue water content was decreased definitively when such pressure values at two compartments were equalized due to augment of the tissue pressure component.

3) Decreasing of cerebral blood flow demonstra-ted in spite of relatively higher value of cerebral perfusion pressure.

From these findings the authors speculated that a higher pressure in the ventricular system will be a driving force, by which the enlargement of ventricular system was induced.