Evaluation of the lumbar and ventricular infusion test in the diagnostic strategy of pediatric hydrocephalus and the therapeutic implications

Aim To evaluate the infusion test as a diagnostic tool behind the choice of intervention in pediatric hydrocephalus. Materials and methods Intracranial pressure (ICP) measurement and infusion test were performed intraventricularly, by lumbar route, or combined in 40 consecutive children as a part of the standard diagnostic program in 1996-1999. Results The median age was 18.5 months, ranging from 2 weeks to 13 years. In the subgroup of patients with radiological aqueductal stenosis (N=14), mean lumbar/intraventricular ICP was 13 (3-35)/10 (2-27). Mean lumbar/ventricular Rout were 18 (4-49)/17 (6-37). For patients with radiological communication between the third and fourth ventricles (N=14), the mean lumbar/intraventricular ICP was 11 (7-17)/9 (1-16). Mean lumbar/ventricular R-out were 8 (3-11)/8 (4-12). A total of 13 patients had a shunt insertion, 10 had an endoscopic third ventriculostomy (ETV), 5 had endoscopic fenestration of a cyst, and 12 had no surgery. Of the patients initially treated with EVT, 50% had a shunt insertrion shortly after. For communicating hydrocephalus, 75% of the patients initially not operated based on normal Rout values ended up having a shunt insertion. Discussion R-out has doubtful value as an indicator for conducting an operation or not and in the choice between EVT and shunt in chiladren. This should be interpreted in the light of a growing understanding of hydrocephalus on a molecular level.