What is Normal Pressure Hydrocephalus?
Normal pressure hydrocephalus is an adult onset form of hydrocephalus. It develops slowly over time and therefore differs from other types of hydrocephalus. This means that the drainage of cerebrospinal fluid (CSF) is gradually blocked, and the fluid buildup occurs slowly. It also means that symptoms often develop slowly and over a long period of time
The gradual buildup of CSF in the ventricles means that the resulting pressure within the brain may not be as much as in other forms of hydrocephalus. However, the “normal” part of the name of this condition is misleading because some patients actually do have changes in pressure (i.e., the amount of pressure is not normal).
Normal pressure hydrocephalus occurs due to a blockage in the areas where the cerebrospinal fluid (CSF) drains after exiting certain structures in the brain (ventricles). Since drainage is blocked, the amount of CSF in these structures starts to accumulate and they become enlarged. These enlarged ventricles can then compress the brain and cause damage to it.
Although normal pressure hydrocephalus can occur at age, it typically occurs in adults over 60 years of age.
Causes of Normal Pressure Hydrocephalus
Normal pressure hydrocephalus can be the result of any condition that blocks the flow of cerebrospinal fluid including:
- Head injury
- Brain tumor
- Bleeding within the brain (e.g., subarachnoid hemorrhage)
- Infection (e.g., meningitis)
- Complications from surgery.
- However many cases have no known cause.