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Normal pressure hydrocephalus (NPH)

Contents of this page:


Central nervous system
Central nervous system
Ventricles of the brain
Ventricles of the brain

Alternative Names    Return to top

Hydrocephalus - idiopathic; Hydrocephalus - adult; Hydrocephalus - communicating; Extraventricular obstructive hydrocephalus

Definition    Return to top

Normal pressure hydrocephalus (NPH) is a rise in cerebrospinal fluid (CSF) in the brain that affects brain function.

Causes    Return to top

Normal pressure hydrocephalus (NPH) is a form of hydrocephalus, also known as "water on the brain," 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.

Symptoms    Return to top

The symptoms often begin slowly.

Early symptoms include:

Symptoms as the disorder gets worse:

Exams and Tests    Return to top

An examination shows walking (gait) changes related to the damage in the brain. Deep tendon reflexes may be increased in the lower legs.

Tests include:

Treatment    Return to top

The goal of treatment is to improve symptoms. The treatment of choice is surgery to place a tube called a shunt that routes the excess CSF out of the brain ventricles.

Treatment may vary depending on the symptoms and how much the therapy relieves them.

Outlook (Prognosis)    Return to top

If there is a known cause and the cause can be corrected, the symptoms may be reversed or at least stopped from getting worse. Without treatment, symptoms often get worse and could lead to death.

Surgical treatment improves symptoms in about 50% of cases. People with minimal symptoms have the best outcome. Other people may have different degrees of disability.

Possible Complications    Return to top

When to Contact a Medical Professional    Return to top

Call your health care provider if you have symptoms of normal pressure hydrocephalus.

Call your health care provider if a person with NPH worsens to the point where you are unable to care for the person yourself.

Go to the emergency room or call the local emergency number (such as 911) if a sudden change in mental status occurs. This may mean that another disorder has developed.

Prevention    Return to top

Treating disorders that lead to NPH may prevent it in some cases. It may not be preventable in other cases, but early treatment may prevent severe symptoms.

References    Return to top

Goetz CG, ed. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: WB Saunders; 2007.

Update Date: 2/13/2008

Updated by: Luc Jasmin, MD, PhD, Departments of Anatomy & Neurological Surgery, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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