Normal pressure hydrocephalus (NPH) is an excess amount of fluid within the brain. The fluid builds up in space inside the brain known as ventricles. The pressure in the skull stays normal. However, the fluid in the ventricles alters the brain tissue. This can lead to a range of symptoms.
cerebrospinal fluid (CSF) is fluid that surrounds the brain and spine. It should flow freely around the brain and spine. Injuries, disease, tumor, or infections may block the flow of fluid. There may also be a problem with how the fluid is reabsorbed. This may lead to NPH. Some people will have no clear cause of NPH. This is called idiopathic NPH.
NPH is most common in older adults though it can occur at any age. Health issues that may increase the risk of some types of NPH include:
- Bleeding in brain
- Head trauma
- Brain tumor
Symptoms may include:
- Problems walking
- Decline in thought process and reasoning
- Loss of interest in daily habits
- Loss of short-term memory
- Problems with bladder control
The doctor will ask about symptoms and past health. A physical exam will be done. Other conditions can create similar symptoms. Tests will help to diagnose NPH. Tests may include:
- Cognitive tests—to determine which areas of thought process are affected
- MRI test—images of the brain
- Lumbar puncture—to measure pressure and look for infections or problems in the CSF
A large amount of fluid may be removed during the lumbar puncture. It may create a brief relief of symptoms. This result will help to guide treatment plan.
The goal of treatment is to ease the pressure on the brain.
A surgery may be done to place a shunt in the brain. The shunt will drain fluid out of the brain, down a tube, and into the belly. The cavities in the brain will shrink and symptoms should ease. The shunt will need long-term follow-up care.
Surgery may not be an option for everyone. Additional lumbar punctures may be done to drain excess fluids.
Family Doctor—American Academy of Family Physicians https://www.familydoctor.org
Hydrocephalus Association http://www.hydroassoc.org
Canadian Neurological Sciences Federation http://www.cnsfederation.org
Spina Bifida and Hydrocephalus Association of Canada http://sbhac.ca
Normal Pressure Hydrocephalus. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/normal-pressure-hydrocephalus-nph . Updated September 20, 2019. Accessed October 11, 2019.
Normal Pressure Hydrocephalus. National Institute of Neurological Disorders and Stroke NINDS website. Available at: https://www.ninds.nih.gov/Disorders/All-Disorders/Normal-Pressure-Hydrocephalus-Information-Page. Updated March 27, 2019. Accessed October 11, 2019.
Oliveira LM, Nitrini R, Román GC. Normal-pressure hydrocephalus: A critical review. Dement Neuropsychol. 2019 Apr;13(2):133-143.
- Reviewer: EBSCO Medical Review Board David L. Horn, MD, FACP
- Review Date: 11/2019
- Update Date: 11/12/2019