Normal Cerebral Spinal Fluid Flow

This animation shows how the csf flows. Most of the csf is produced in the body of the lateral ventricle. Normally, it will flow from the lateral ventricle down through the foramen of Monroe into the III ventricle. From there it proceeds down the aqueduct into the IV ventricle. There are three openings in the IV ventricle: laterally are the foramen of lushka and medially or in the middle is the foramen of magendie. Place your mouse arrow over the picture on the left and click the left arrow to start the animation.

Communicating Hydrocephalus

Communicating hydrocephalus develops when there is more fluid being produced than can be absorbed. The ventricular system enlarges to hold the excess fluid. This compresses the surrounding brain tissue. It is like having a partially clogged drain --- the faucet is delivering water faster than the drain can remove the water. For example, sometimes due to scarring from infection or bleeding the cerebral spinal fluid absorption pathways are no longer able to absorb as much fluid as they had prior to the scarring. Fluid accumulates and the ventricular system expands.

Communicating Hydrocephalus may result from various types of hemorrhages. There are examples of this on the web site and may be found under the following links on the home page: Post Hemorrhagic, Subarachnoid Hemorrhage, Other Hemorrhage. There is a special case of Communicating Hydrocephalus called Normal Pressure Hydrocephalus. This is also discussed.