水頭症における髄液amine metabolitesの変動

HYDROCEPHALUS AND AMINE METABOLITES IN THE CSF (A PILOT STUDY)

Ｉ．はじめに

　1960年，AshcroftとSharman^8）が，乳幼児の進行性水頭症において，側脳室より採集した髄液の5-Hydro-xyindoleacetic acid （5-HIAA）が著るしく増加していることを報告，その後，水頭症に伴う髄液のaminemetabolitesの変動が諸家により検討され，5-HIAAの変動を指標として，水頭症に対する短絡手術の適応や既設短絡路の作動状態の判定なども行われるようになつてきたが，本邦においてはかかる面での報告をみず，また従来の諸家の検討は専ら乳幼児の急性水頭症を対象として進められており，成人の二次性水頭症における記載も見当らない。

　われわれは今回脳腫瘍やクモ膜下出血等に基づく二次性水頭症例をも含め水頭症における髄液中のamine me—tabolitesを定量し，一次性，二次性を問わず，進行性水頭症においては諸家指摘の如く髄液の5-HIAAの増加を認めたが，更に水頭症が陳旧化し，脳の荒廃の進んだ症例や代償性水頭症（Hydrocephalus exvacuo）の範疇に入ると思われる症例では，逆に髄液amine meta—bolitesが低値を示す所見を得たので，短絡手術適応の問題を含め，水頭症の治療に関し若干の考察を加え，ここに報告する。

The concentrations of the amine metabolites (5-HIAA, HVA and DOPAC) in cerebrospinal fluid were estimated in infantile hydrocephalus and in patients with symptomatic hydrocephalus due to various brain diseases.

As has been reported by previous investigators, it was noted that the 5-HIAA concentrations in ventricular CSF were extremely high in cases with progressive hydrocephalus and a diminished level of 5-HIAA was measured after surgery with a functioning shunt. Contrariwise, CSF levels of 5-HIAA and HVA were low in some cases of non-progressive or arrested hydrocephalus where the brain thought to have devastated owing to the long-lasting distension of the ventricular system.

It is sometimes difficult to determine whetherthe hydrocephalus is progressive or has arrested. There also exist many controversial problems to differentiate a treatable form of the normal pressure hydrocephalus described by Adams et al. The differentiation between the hydrostatic hydroceph-alus and the atrophy secondary to brain distension is not always possible, even with the addition of isotope cisternography. In these respects, the estimation of amine metabolites in CSF will provide many valuable informations. A rising level of 5-HIAA in ventricular CSF may be an important indication to operate. In cases with low CSF levels of 5-HIAA and HVA, there seems to be little likelihood of improvement by surgical treatment.

In some patients showing low concentrations of amine metabolites, an administration of amine pre-cursors (L-dopa, L-5-HTP) could be reasonably effective in ameliorating a clinical picture (such as a akinetic mute state and so on), because CSF levels of amine metabolites provide an index of turnover of the parent amine in brain and the biogenic amines may serve as synaptic transmitters or modulators in the central nervous system.