Definition

Hydrocephalus is too much fluid in the brain. The fluid is called cerebrospinal fluid (CSF). It is a clear fluid that normally surrounds both the spinal cord and the brain. It is also in the ventricular system of the brain. With hydrocephalus the ventricles, or spaces, become enlarged.

You may be born with hydrocephalus, or it may develop after an injury or illness.

Causes

Hydrocephalus occurs when:

• A blockage doesn’t allow CSF to drain properly
• Another condition, such as bleeding, inflammation, or infection, makes the brain unable to resorb fluid
• An excess of CSF is produced

These problems with the CSF may be caused by:

• Brain tumors
• Cancer
• Inflammation in the CSF
• Cysts in the brain
• Malformations of the central nervous system, such as:
  • Dandy-Walker syndrome
  • Arnold-Chiari malformation
  • Spina bifida
• Brain injuries
• Infections of the brain or meninges, such as encephalitis or meningitis
• Problems with the blood vessels in the brain, such as aneurysms or arteriovenous malformations
• Bleeding into the brain or CSF space

Risk Factors

Factors that may increase your chance of hydrocephalus include:

• Neural tube defects
• Mother has infection during pregnancy, such as:
  • Cytomegalovirus
  • Toxoplasmosis
  • Lymphocytic choriomeningitis virus
  • Chickenpox
  • Mumps
• Brain infections
• Malformations of the brain
• Brain injuries
• Brain hemorrhage

Symptoms

Symptoms depend on the severity of the hydrocephalus. The extra CSF puts pressure on the brain. Symptoms may start out mild and become more severe as CSF pressure increases.

Symptoms may include:

• Headache, which may often be worse when lying down, upon first awakening in the morning, or with straining
• Nausea and vomiting
• Problems with balance
• Difficulty walking
• Poor coordination
• Difficulty controlling urination
• Personality changes
• Confusion
• Memory problems
• Loss of consciousness
• Death

In babies, symptoms may include:

• Large head circumference
• Bulging fontanelle on the head
• Slow development
• No longer able to do activities they once could do

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done.

Tests to examine the internal structure of the brain may include:

• CT scan
• MRI scan
• Ultrasound in children up to 15-18 months old with open anterior fontanelles

Treatment

Talk with your doctor about the best treatment plan for you. Options include:

• Ventriculoperitoneal shunt allows excess CSF to drain into another area, usually the abdomen. Sometimes a temporary extraventricular drain (EVD) is placed.
• Third ventriculostomy allows CSF to flow out of the area where it is building up by creating a hole in an area of the brain.
• Removal of the obstruction of CSF flow.
• Medication to decrease the production of CSF or to reduce swelling.
• Lumbar puncture to remove excess CSF.

People who have increased risk for hydrocephalus should be carefully monitored. Immediate treatment might prevent long-term complications.

Prevention

There are no current guidelines to prevent hydrocephalus, but you can decrease your risk of developing it. In general:

• Take folate before pregnancy to reduce the chances of neural tube defects and myelomeningocele (a type of spina bifida).
• Get regular prenatal care.
• Keep your child’s vaccines up to date.
• Protect yourself or your child from head injuries.

To prevent certain infections in the mother during pregnancy, take these steps:

• Talk with your doctor about updating your vaccines.
• Carefully cook meat and vegetables.
• Correctly clean contaminated knives and cutting surfaces.
• Avoid handling cat litter, or wear gloves when cleaning the litter box.
• Avoid rodent contact.

National Institute of Neurological Disorders and Stroke http://www.ninds.nih.gov

Spina Bifida and Hydrocephalus Association of Canada http://www.sbhac.ca

Hydrocephalus in children. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated July 23, 2014. Accessed September 30, 2014.

Hydrocephalus fact sheet. National Institute of Neurological Disorders and Stroke website. Available at:
http://www.ninds.nih.gov/disorders/hydrocephalus/detail_hydrocephalus.htm
Updated April 16, 2014. Accessed September 30, 2014.