Normal pressure hydrocephalus

Overview

Normal pressure hydrocephalus (often shortened to NPH) is a rare neurological condition caused by a build-up of an excess amount of cerebrospinal fluid in the chambers (or ‘ventricles’) of the brain.

The normal function of cerebrospinal fluid is to act as a cushion to protect the brain and spinal cord tissue from injury, and to distribute nutrients to the brain. A blockage may result in an abnormal accumulation of cerebrospinal fluid in the ventricles.

As a result of the fluid build-up, the ventricles may become enlarged; this can cause brain tissue to be damaged or destroyed. If this fluid build-up is left untreated, NPH may cause physical and cognitive changes affecting a person’s movement, thinking and bodily functions.

Symptoms

Symptoms of NPH appear mainly in people over the age of 60, but can occur at any age.

There are three main symptoms that are common in people living with NPH:

1. Problems with gait (e.g., walking difficulties),
2. Dementia, and
3. Loss of bladder control.

Problems with gait (e.g., walking difficulties)

People living with NPH may have difficulty lifting their feet when they are walking and tend to walk with their legs wide apart and their body bent forward. They do not lift their feet, as if their feet are stuck to the ground.

Difficulties with gait in people with NPH can range from mild balance concerns to the inability to walk at all.

Dementia-related symptoms

As the condition progresses, a person living with NPH may begin to experience symptoms of dementia such as:

• Forgetfulness,
• Short-term memory loss,
• Impaired decision-making abilities,
• Apathy,
• Lack of concentration, and
• Changes in mood and behaviour.

Loss of bladder control

In addition to these other symptoms, people living with NPH may experience problems controlling their bladder.

If NPH goes untreated, a person's symptoms can become progressively worse with time.

Diagnosis

There is no single test to diagnose NPH. Making a diagnosis can be challenging as there are a number of symptoms that NPH shares with other dementias.

Physicians assess patterns and types of symptoms, as well as review the person’s complete medical history to rule out other conditions, such as Alzheimer’s disease or Parkinson’s disease.

Brain imaging (MRI or CT scan) is often used to detect any abnormal growth in the brain’s ventricles. A spinal tap (collecting a small amount of cerebrospinal fluid from the spine) may be completed to measure the pressure of the cerebrospinal fluid and whether the walking improves.

A thorough assessment may also include neuropsychological testing to evaluate the impact of symptoms on the person’s mental abilities.

Risk factors

In most cases of NPH, the reasons for the build-up of cerebrospinal fluid in the brain’s ventricles are unknown.

Treatment

The most common treatment to reduce symptoms associated with NPH is to insert a tube (called a ventriculoperitoneal shunt) to drain the excess cerebrospinal fluid from the brain to the abdomen.

This surgical procedure is most likely to help improve the walking abilities of a person with NPH. Symptoms related to a person’s cognitive function and bladder control can improve from the shunt being inserted in the brain.

Currently, there is no known nonsurgical cure for NPH. Medications that are often used to reduce excess fluid in the body have not been found to be effective in treating NPH.

More information and resources

Hydrocephalus Canada. Hydrocephalus Canada provides information and support for individuals affected by hydrocephalus and spina bifida and their families.