FLUID-DYNAMICS OF THE CEREBRAL AQUEDUCT

Despite a multitude of theories describing the mechanics of the intrac ranial spaces in diseases such as hydrocephalus, little is known about the mechanics of normal CSF flow. A pressure difference is required t o drive CSF flow. Knowing that the pressure difference driving fluid t hrough the aqueduct is beyond the resolution of clinically used pressu re transducers, a computational fluid dynamics program was used to ana lyze flow through an aqueduct shape. Flow through this duct was compar ed with that through a cylinder and through a double hourglass. Both s teady and oscillating flows were tested, revealing that only 1.1 Pa of pressure is required to move CSF through the aqueduct. This suggests that normally less than 5% of the total resistance to CSF flow within the CSF pathways occurs in the aqueduct.