A longitudinal study of shunt function in 360 patients with hydrocephalus.

Data from an eight-year clinical study of shunt-treated hydrocephalus indicated continued shunt dependency in 289 of 360 patients. 919 combined pressure-radionuclide clearance studies were performed. In 307 studies in which the shunt was identified as nonfunctional, 208 patients were symptomatic for increased intracranial pressure and had the shunt revised. Of the other 99 patients, 71 have remained asymptomatic for three to 60 months (mean 27 months) and 28 subsequently required shunt revision after one to 67 months (mean 24 months). Five other clinical patterns are described. Various methods of monitoring shunt function are recommended.