Normal pressure hydrocephalus (NPH) - Overview
Hydrocephalus - idiopathic; Hydrocephalus - adult; Hydrocephalus - communicating; Extraventricular obstructive hydrocephalus
Definition of Normal pressure hydrocephalus (NPH):
Hydrocephalus refers to a build-up of fluid inside the skull, leading to brain swelling. Hydrocephalus means "water on the brain."
Normal pressure hydrocephalus (NPH) is a rise in cerebrospinal fluid (CSF) in the brain that affects brain function. However, the pressure of the fluid is usually normal.
Causes, incidence, and risk factors:
Normal pressure hydrocephalus (NPH) is a form of hydrocephalus, which means there is too much fluid pressing on the brain.
NPH can occur without a known cause, or it may be caused by any condition that blocks the flow of cerebrospinal fluid (CSF). The fluid-filled chambers (ventricles) of the brain enlarge to fit the increased volume of CSF. They press down on and damage or destroy brain tissue.
Risk factors include:
CSF is produced in normal amounts in these conditions, but it is prevented from being reabsorbed normally.
NPH is thought to account for about 5% of all dementias.
- Reviewed last on: 3/9/2010
- Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Rosenberg GA. Brain edema and disorders of cerebrospinal fluid circulation. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann; 2008:chap 63.
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