MOVEMENTS OF VENTRICULAR FLUID LEVELS DUE TO CEREBROSPINAL FLUID FORMATION

Abstract

Experiments in dogs and observations on human subjects during pneumoencephalography have shown that with the head in the brow-up position, ascending fluid levels in the lateral ventricles are due to active formation of cerebrospinal fluid. This accumulation of cerebrospinal fluid displaces air down the aqueduct and fourth ventricle, which may remain opacified for several hours.Using roentgenographic measurements of the rate of ascent of lateral ventricular fluid levels and a cross-sectional area of the posterior two-thirds of the lateral ventricular bodies, the rate of cerebrospinal fluid formation in the lateral ventricles was calculated in 16 patients. The average cerebrospinal fluid formation for the lateral ventricles was about one-quarter of the accepted total cerebrospinal fluid formation (bulk flow). Possible reasons for this low figure are discussed.