正常圧水頭症—第1報：髄液循環を中心にして

NORMAL PRESSURE HYDROCEPHALUS : Part 1.DYNAMIC STUD OF CSF CIRCULATION IN PATIENTS WITH NORMAL PRESSURE HYDROCEPHALUS

I．はじめに

　近年，正常圧水頭症（normal pressure hydrocephalus：以下N．P．H．と略す）の概念が普及するにつれ，これまでは諸疾患の後遺症として社会的にも見捨てられていた痴呆状態の患者に光明を投じた反面，手術適応の範囲が拡大され過ぎる傾向がみられてきた。また臨床症状は従来言われてきた短絡手術適応の条件を備えているにもかかわらず，手術による症状の改善が認められない症例にしばしば遭遇する。これは，正常圧水頭症の本態がいまだ完全に解明されていないことに最大の原因があると考えられている。

　著者らは，1971年より種々の原因によるN．P．H．患者の脳循環あるいは髄液循環動態を検索し，その一部を既に報告してきた^2,4）が，今回は更に症例を重ねることにより，若干の新知見を得たので報告する。

To clarify the pathogenesis of normal pressure hydrocephalus (NPH), quantitative measurement of CSF dynamics was attempted using RI techniques.

In this study results concerning RI ventriculo-graphy and RI transfer test from CSF to plasma were reported."Barrier ratio"and regional cerebral blood flow study in NPH will be reported else-where. Fifty-three patients with chronic com-municating hydrocephalus were devided into two groups. Thus, twenty-seven cases were diagnosed as NPH according to clinical symptoms and signs, and others were considered as mere chronic com-municating hydrocephalus without any NPH char-acteristics.

Results are as follows;

1) ¹⁶⁹Yb-DTPA ventriculography; In NPH group, there was longer retention of RI injected into lateral ventricle, and RI activity was not de-tected in the cisterna magna 60 minutes after the injection. These findings show remarkable delay of CSF flow in NPH patients.

2) Transfer test of ¹⁶⁹Yb-DTPA from CSF to plasma; Immediately after the RI injection, trans-fer ratio of RI activity from CSF to plasma was measured. It was revealed that intraventricular RI was more rapidly transfered to plasma in NPH group compared with in the control group, sug-gesting accelerated trans-ependymal absorption of RI in NPH group.