The estimation of total 5-hydroxyindoles in CSF and its relationship to hydrocephalus

Abstract

During the last few years, increasing interest has been shown in estimating CSF 5hydroxyindoles in cases of hydrocephalus as an index of increased intra-cranial pressure. It is thought that the values in ventricular CSF are significantly elevated when there is progressive hydrocephalus or a blocked V-A shunt. A common assay procedure involves the measurement of fluorescence developed in CSF under acid conditions, measurements being made at fixed excitation and emission wavelengths. Scanning the excitation wavelength, however, almost invariably shows the presence of an interfering compound which may wholly dominate the values as derived under fixed conditions. Allowing for this interference, our results show poor correlation between intra-cranial pressure and total ventricular CSF 5-hydroxyindoles. Similarly, the ratio of ventricular to lumbar CSF hydroxyindoles do not show a useful correlation. It seems that this line of approach may not be as rewarding as was first indicated by earlier authors.