ABSTRACT
Cerebrospinal fluid (CSF) has an estimated total volume of approximately 150 mL, and the CSF volume is larger in men than women. CSF column is also increased in older individuals than younger individuals due to an increase in ventricular size that compensates for tissue loss with age within an unchanging bony cranium. The first major component is bulk flow along a gradient from the region of production to the region of absorption. The second major component is oscillatory flow compensating for changes in brain volume during systole and diastole. Obstructive hydrocephalus or noncommunicating hydrocephalus results from blockage of the CSF pathway between CSF production in the choroid plexus and CSF resorption over the convexities. The narrowest areas of the ventricular system are the most common points of obstruction with dilation of the ventricular system ‘upstream’ of the obstruction and normal caliber ‘downstream’ of the obstruction.
