Hydrocephalus: Changes in Formation and Absorption of Cerebrospinal Fluid Within the Cerebral Ventricles

Abstract

T HIS paper presents a s tudy designed to measure accurately the changes tha t occur in the formation and absorption of cerebrospinal fluid within the cerebral ventricles during the development of hydrocephalus. The results of these experiments are considered in relation to the evaluation of the hydrocephalic patient. A hydrocephalic infant on ventrieular drainage will produce several hundred cc. of cerebrospina] fluid per day, but the ventrieular rate of growth in rapidly progressing hydrocephalus is only of the order of 10 to 15 co. a day, only a small fraction of the amount of fluid being formed. Clearly, therefore, there mus t be intraventrieular absorption of fluid. At tempts have been made to measure absorption of cerebrospinal fluid for the evaluation of hydrocephalus by measuring the disappearance of tracers from the fluid, but this method has been shown to be wrong fundamental ly3 The data required to evaluate the outflow of cerebrospinal fluid or absorptive mechanism mus t include information about the rate of formation of the bulk of the fluid and how it can change. W h a t is the max imum production of cerebrospinal fluid tha t the system of outflow mus t handle? There also mus t be information about the resistance to outflow of the bulk of cerebrospinal fluid (or absorption) and the total absorpt ive capacity. With these da ta an accurate assessment can be made of the