HyFI -- Facts

Welcome to The Hydrocephalus Foundation, Inc. (HyFI)

Facts About Hydrocephalus

What is Hydrocephalus?

Hydrocephalus is an abnormal buildup of the brain’s normal water-like fluid (cerebrospinal fluid or CSF).

What is cerebrospinal fluid (CSF)?

Cerebrospinal Fluid is a clear fluid that bathes the brain and spinal cord, providing a cushion, nutrients and carrying away waste.

This fluid is made in the ventricles of the brain. The fluid then flows through a canal-like pathway over the upper surface of the brain where it enters the veins through tiny openings called arachnoid villi.

How is hydrocephalus diagnosed?

The most common ways for diagnosing hydrocephalus are the CT (computerized tomographic) scans and MRI (magnetic resonance imaging). They can accurately measure the size of the fluid spaces, or ventricles, within the skull.

In special circumstances, a variety of other tests may be used.

How can a person get hydrocephalus?

Although generally not hereditary, hydrocephalus is either present at birth (congenital) or a result of an injury or trauma to the brain (acquired).

What are the two forms of hydrocephalus?

Hydrocephalus presents in one of two forms:

Non-communicating hydrocephalus is caused by a blockage in the ventricular pathway through which the CSF flows.
Communicating hydrocephalus is caused by the poor absorption of CSF when the pathways are not obstructed.

Can you cure hydrocephalus?

No, you can usually just treat hydrocephalus.

How do you treat hydrocephalus?

The most common way is the surgical diversion of the excess fluid by placing a synthetic tube (shunt) into the ventricle.

What is a shunt?

A shunt is a tube that diverts the excess fluid from the expanded brain cavity (ventricle) to another part of the body. This procedure re-directs the fluid to another body cavity such as the abdomen. In most cases, the fluid is diverted to the peritoneal cavity in the abdomen or one of the chambers of the heart.

A shunt is usually composed of three parts: a silicone catheter that enters the enlarged ventricle; a one-way valve that only allows flow away from the ventricle; and tubing which enters the cavity that is to receive the fluid. Each valve is designed to operate at a set pressure, so that a high-pressure valve will allow less fluid to flow through it than a low-pressure valve. A variety of valve designs are available and efforts are constantly underway to improve them. The entire shunt system is placed underneath the skin.

Although, shunting systems represent a major medical breakthrough, patients are still left vulnerable to complications, most notably obstruction or infection of the shunt. However, most people diagnosed with hydrocephalus live full and active lives.

Can a shunt break?

Despite their success rate, shunts have potential problems. The most common complications are:

Bacterial infection and
Obstruction.

Infected shunts are treated with antibiotics and the removal and replacement of the system. Infections are typically accompanied by fever, redness and swelling along the tubing under the skin. Drainage of infected liquid (pus) from one of the incisions used to insert the shunt may also occur.

When a shunt is obstructed it no longer is able to drain fluid from the ventricles. This results in elevated intracranial pressure, causing headache, vomiting, lethargy, and sometimes double or blurred vision. Frequently such elevated pressure can be relieved temporarily by draining the shunt’s valve or reservoir with a needle. However, an operation to replace part or all of the shunt is generally required.

It is important for people with shunts to maintain contact with their neurosurgeon to ensure quick and accurate assessment of any problems that may arise.

Are there other ways to treat hydrocephalus?

A procedure that may be an effective alternative to shunt placement is a Third Ventriculostomy

What is a third ventriculostomy?

Third Ventriculostomy is a one-time procedure; unlike shunt surgeries which in most cases are numerous. A Third Ventriculostomy consists of creating a small hole, about one millimeter in diameter in the wall of the third ventricle. This allows the CSF to once again flow. A Third Ventriculostomy is not available for all people with hydrocephalus.

What problems are usually associated with hydrocephalus?

There are many problems that can be associated with hydrocephalus and they vary from person to person. Some problems may be:

Learning disabilities. Although individuals are able to learn, they may require special modifications and assistance.
Memory deficits
Psychological deficits
Motor Skill disabilities
Vision problems
Hearing difficulties,
Seizures, and
Hormonal imbalances.
Sensitivity to sound, pressure and bright lights may also be associated with the condition.

Because each case is individualized, generalizations in this category are difficult to make.

What are the potential future issues for a person/family affected by hydrocephalus?

Financial strain caused by numerous medical appointments and or surgical procedures can create financial problems.
Private insurance may not be attainable unless offered by a large group employment policy.
Additional concerns about a child's ability to grow into a self-sufficient adult may also be evident.

What are the symptoms of hydrocephalus?

Regardless of the cause of hydrocephalus, increased intracranial pressure in the skull causes a common set of signs and symptoms that vary depending on the age and physical condition of the patient.

In newborns or young infants, the head may enlarge or the fontalle (soft spot) may bulge because the cranium is not yet solidified and will expand due to the increased pressure. However before such dramatic head growth is apparent, prominent scalp veins, vomiting and irritability may be observed.

In older children and adults with a developed and solidified cranium, the symptoms of hydrocephalus may include personality changes, headache, vomiting, lethargy, irritability, and a loss of interest in daily activities. Gait disturbance and disrupted coordination may occur.

Because increased pressure has a direct impact on the optic nerves, patients often experience vision problems. The excess pressure may also have a direct bearing on the hypothalmus that can alter growth and sexual development. Fluid and electrolyte imbalance may also occur.

Are there other medical conditions that may be associated with Hydrocephalus?

Yes, some of the most common are:

Arachnoid Cysts
Brain Injury
Dandy-Walker Syndrome
Head Trauma
Meningitis
Porencephaly
Tumors
Spina Bifida

What is Normal Pressure Hydrocephalus?

Normal Pressure Hydrocephalus (NPH) is the enlargement of the ventricles of the brain, without increased Cerebrospinal Fluid (CSF) pressure.

What are the symptoms of NPH?

In most instances, NPH causes dementia, difficulty walking and urinary incontinence. Because NPH is most common in elderly patients, its symptoms may be confused with Alzheimer's disease or Parkinson’s. Although NPH causes deficiencies in short term memory and a gradual loss in the think clearly, the changes are not as severe as those associated with Alzheimer's disease.

How is NPH diagnosed?

Because there is no known cause for NPH and the symptoms are non-specific and insidious, a diagnosis is often difficult to make. A Computed Tomographic (CT) scan or a Magnetic Resonance Imaging (MRI) scan provides pictures of the ventricles and ensures that the CSF flow is not blocked by a tumor or other mass. Additional tests may be used including CSF diffusion studies and repeated lumbar punctures to drain spinal fluid. Although tests alone cannot predict whether a shunt will improve the condition of NPH patients, the decision to place a shunt is based on the extent of symptoms.