A buildup of cerebrospinal fluid (CSF) in the cavities, or ventricles, of the brain can result from a head injury, a stroke, an infection of the protective layer of issue surrounding the brain known as the meninges, a brain tumor and even after surgery on the brain.
In most cases, the exact cause of NPH is not known. However, our UC Irvine Health neurosciences team is conducting research to study whether there is a relationship between traumatic brain injury, abnormal CSF flows and NPH.
NPH symptoms are usually subtle at first then worsen gradually as fluid builds up in the brain's ventricles.
In a healthy brain, as in the image at left below, cerebrospinal fluid (CSF) fills only a small proportion of the cranium. When CSF doesn't drain normally, as in the image at right below, it presses on delicate neurological tissues in the brain.
This in turn causes problems with cognition and bodily functions, producing the classic signs of difficulty walking and controlling urination.
Gait symptoms include:
- Unsteadiness and leg weakness
- Abnormal gait, including shuffling
- Sudden falls
- Trouble taking a first step, the sensation that feet are stuck to the floor
- Freezing while walking
Urinary symptoms include:
- Frequent urination
- Urgency to urinate
Mild dementia symptoms include:
- Memory loss
- Speech difficulties
- Apathy and withdrawal
- Changes in mood or behavior
- Problems with attention, reasoning or judgment
- Difficulty concentrating and completing tasks
Other symptoms may include:
Some of these symptoms may be viewed as part of the normal aging process. But NPH should be considered as a possibility when urinary tract problems combine with walking and dementia-like symptoms.
To assess your condition and rule out other potential causes for NPH symptoms, we conduct:
- A detailed neurological exam, which includes tests to determine your ability to answer questions and follow simple instructions
- A neuropsychological test, if needed, to assess symptoms of mild dementia
- Imaging tests to get detailed views of the structures of the brain
Working closely with UC Irvine Health neuroradiologists, we use magnetic resonance imaging (MRI) to detect any enlargement of ventricles and to measure the flow of cerebrospinal fluid through the cerebral aqueduct. Any blockage of CSF can lead to hyperdynamic flows that are frequently seen in patients with NPH.
The MRI is a painless, non-invasive test that is safe for most people. However, patients with cardiac pacemakers or other metallic implants may not be able to have an MRI, which uses a strong magnetic field to create images. A CT scan might be used instead to determine whether the ventricles are enlarged.
Once it is determined that your symptoms are likely caused by a buildup of CSF, we will consider whether implanting a shunt can alleviate the problem.
At UC Irvine Health, we have a team of specialists to help guide our patients through the process. This includes a peri-operative team to help coordinate care to make your surgery safer and your hospital stay more comfortable.
A common treatment for NPH is the surgical placement of a tube in the brain known as a shunt that will drain the excess fluid.
The shunt is usually inserted into a ventricle in the brain and the tube is passed under the skin from the head through the neck and chest to the abdomen, where the body absorbs the excess CSF.
The shunt has a valve that allows fluid to flow when pressure builds in the brain. More modern shunts allow for valve adjustment without the need for another surgical procedure.
Our UC Irvine Health neurosurgical team is able to monitor the fluid flows with the non-invasive ShuntCheck III© sensor system and, when necessary, adjust the valve without the need for another surgical procedure.
We also use MRI CSF flow studies to help assess shunt function after implantation.
Implanting a shunt doesn’t cure the underlying cause of NPH, but it may relieve the symptoms for many people.
In some people, symptoms may improve, but gradually worsen over time.
People with milder symptoms generally respond better. Prompt diagnosis and treatment of NPH can improve the chances of a good result.
Surgical complications can include bleeding and infection. It’s important to follow your physicians’ directions after discharge.
We follow the progress of all our NPH patients to ensure that their programmable shunts are performing optimally. We use ShuntCheck III to make regular assessments of how well excess CSF is flowing from the brain's ventricles.