5-hydroxyindoleacetic acid (5-HIAA) levels in the cerebrospinal fluid of hydrocephalic children before and after ventricular shunting procedure.

21 cases of hypertensive hydrocephalus were investigated for lumbar 5-HIAA before and after operation. Seven groups (posterior fossa tumors) of patients aged between 2 and 12 years were tested after tumor removal; the others (nontumorous hydrocephalus) after ventricular shunting. This last group included 8 patients with noncommunicating hydrocephalus aged between 15 days and 12 years and 6 with communicating hydrocephalus aged between 6 months and 9 years. At the time of the second determination all patients presented an improvement of clinical signs of intracranial hypertension. A correlative analysis of 5-HIAA values before and after operation is made. In tumor cases, preoperative levels were higher than controls, and a significant decrease was found after operation in comparison with preoperative levels. In nontumor cases, a significant decrease was also observed in noncommunicating hydrocephalus, confirming clinical usefulness of the results for controlling the degree of the intracranial hypertension and, in consequence, shunt performance. In communicating cases the results were disappointing, because almost always postoperative levels did not differ from the preoperative ones. Possible interpretations of the data are analyzed.