A blockage or narrowing of the pathway from the third to the fourth ventricle.

Resembles a cobweb membrane which covers the brain and spinal cord.

Protrusions of the arachnoid membrane of the brain. The arachnoid villi (or granulations) are very similar to a one-way valve, as they allow the CSF to drain from the subarachnoid space into the superior sagittal sinus, where it can be reabsorbed into the blood system.

Small, flexible tube (part of the shunt system) inserted into the body part (i.e. ventricle), which allows the passage of the Cerebrospinal Fluid.

The clear water-like fluid that bathes the brain and spinal cord. The fluid provides nourishment, carries away any debris (such as excess protein cells), and protects us from injury. It is in constant production, circulation and absorption. The body makes almost a pint of CSF daily.

Scan of the head using an X-ray beam, which passes through the head allowing the computer to make a picture of the brain in slices. A CT Scan will show if the ventricles are enlarged or if there is a blockage.

Deterioration of intellectual faculties, such as memory, concentration, and judgment. Dementia can also be caused by a head injury, medication, stroke, or another medical condition (such as Alzheimer’s or Hydrocephalus).

This device is somewhat similar to a shunt, although it is on the outside of the body. A catheter is implanted into the brain to drain the excess CSF. The flow can be regulated by either raising or lowering the bag where the fluid is emptied into.

See Cerebral Ventricles.

Is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under increased pressure and can compress and damage the brain. Hydrocephalus can arise in utero, at the time birth, or any time afterward.