Resulting from an outside factor; not inherited nor congenital.

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

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.

An accumulation of CSF found on the outside of the brain, which usually presents itself at birth or soon thereafter. Head size will increase, but scans show no internal problems in the ventricles or pathways. Condition corrects itself within about 18 months of age (of the child).

The water-type fluid that bathes the brain and spinal cord.

Closed spaces that serve as reservoirs at the base of the brain that bathe the surfaces of the brain and spinal cord, and then is absorbed into the bloodstream.

A type of hydrocephalus where the pathways and the ventricular system are not obstructed; however, the problem appears to be that of re-absorption of the used CSF.

A child diagnosed in utero or at the time of birth as having hydrocephalus.

Identification of a disease or disorder by a physician.

The catheter connected to the shunt valve and directed to the point where the CSF can drain and be re-absorbed.

A hole in the bony covering of the spinal cord through which portions of the brain, spinal cord or meninges may herniate.

A surgery in which a hole is punctured in the floor of the third ventricle to allow a new pathway for the CSF to be absorbed by the body.

Derived from the Greek words "hydro" meaning water and "cephalus" meaning head, a condition in which the primary characteristic is excessive accumulation of fluid in the brain.

A bleed within the ventricular system of the brain (also referred to as a brain bleed).

There are two- one on each side of the brain.

The insertion of a hollow needle to remove some of the CSF, either for pathological testing (i.e. for infection) or to relieve some pressure and see if the patient improves.

Drowsy inactive reluctance or inability to move or respond to stimuli.

An infection of the lining of the brain.

Type of hydrocephalus where the ventricles are enlarged but there is no obstruction in the ventricular system. The cause appears to be that the CSF is not being absorbed.

Type of hydrocephalus where the ventricles are enlarged but there is no obstruction in the ventricular system. The cause appears to be that the CSF is not being absorbed.

Swelling of the optic disk, which is part of the optic nerve.

Probable outcome of a disease.

Type of shunt where the physician can raise or lower the amount of CSF taken from the brain.

A catheter that is placed in the ventricle of the brain.

Part of the shunt where the CSF is stored and then released periodically.

When an operation is needed to replace part or all of the shunt.

A tube implanted in the cranium to balance the flow of cerebrospinal fluid; used in the treatment of hydrocephalus.

A condition that is present at birth which can affect the development of the back bones, spinal cord, surrounding nerves, and the fluid-filled sac.

Space where CSF travels over the surface of the brain and the spinal cord.

Unit of measurement to determine the strength of a magnet.

Inability to hold urine in the bladder.

Controls how much CSF is taken from the brain.

Fluid filled regions inside the brain.

Type of shunt where the distal catheter tip lies in the right atrium of the heart which allows the CSF to enter the bloodstream directly.

Type of shunt where the distal catheter is located in the pleural space that surrounds the lungs.

Type of shunt where the distal catheter is located in the lower part of the abdomen.