Emergency Neurological Conditions

Hydrocephalus

Cerebrospinal fluid is a watery fluid produced by the brain. The brain produces CSF at the rate of 20cc an hour. CSF is reabsorbed by the body along the surface of the brain. The fluid circulates in the fluid filled spaces inside the brain, called ventricles, around the brain and around the spine, providing a cushion. Accumulation of fluid in the brain, hydrocephalus, occurs when the brain’s ability to circulate or reabsorb CSF is compromised. Communicating hydrocephalus is common in subarachnoid hemorrhage. The blood on the undersurface of the brain impairs the brain’s ability to reabsorb CSF and it accumulates, although there is no obstruction to its circulation. Obstructive hydrocephalus occurs when there is an obstruction to the normal circulation of CSF in the brain. Although absorption is normal the CSF accumulates because it cannot circulate to the re-absorption point.

Hydrocephalus is treated by inserting a small catheter through the skull and into the CSF filled space (ventricles) of the brain. The catheter is connected to tubing, which drains into a small bag outside of the patient. This procedure is called a ventriculostomy. Ventriculostomy is a very effective method of preventing accumulation of fluid in the brain and avoiding or treating the resultant increase in brain pressure. The ventriculostomy catheter will stay in the patient until the brain regains its ability to properly circulate or reabsorb CSF. If the condition does not return to normal a permanent catheter is placed.

Permanent drainage of CSF requires a ventriculoperitoneal (VP) shunt. A VP shunt has two limbs. One limb is a catheter placed through a small hole in the skull, into the brain, identical to a ventriculostomy. The other limb is tubing, connected to the ventriculostomy catheter. The tubing, however, is tunneled under the skin and into the abdomen, or peritoneal cavity, where the abdominal lining reabsorbs the CSF.