Concentration of homovanillic acid and 5-hydroxyindoleacetic acid in the ventricular cerebrospinal fluid of patients with obstructive hydrocephalus.

In 12 patients with different posterior fossa tumours the concentrations of homovanillic acid (HVA) and of 5-hydroxyindoleacetic acid (5-HIAA) were measured in cerebrospinal fluid from the lateral ventricles. All patients had obstructive hydrocephalus. Patients with a clear increase of 5-HIAA/HVA ratio in the ventricular CSF have died subsequently. This feature may have a diagnostic value, and indicates the prevalence of serotoninergic neurones in patients with obstructive hydrocephalus with fatal course after surgery.