Normal Pressure Hydrocephalus (NPH)
Normal pressure hydrocephalus (NPH) is an abnormal buildup of cerebrospinal fluid (CSF) within the cavities of the brain, which are called ventricles.
Every day, the average adult produces about one pint of CSF, which protects the brain from injury and carries nutrients to and waste products away from the brain. In NPH, this fluid is produced in normal amounts, but it accumulates instead of being reabsorbed. The ventricles swell to accommodate the increased volume of CSF, and this swelling compresses brain tissue. This pressure can damage or destroy parts of the brain.
How common is normal pressure hydrocephalus?
It is estimated that more than 700,000 Americans have NPH, but less than 20 percent of them receive an appropriate diagnosis.
Who gets normal pressure hydrocephalus?
NPH can occur at any age, but it is most common in older adults. The normal aging process can lead to softening of the brain, causing ventricles to expand as a result of fluctuations in the amount and pressure of CSF.
NPH can also develop as a result of:
- Head trauma
- Cranial surgery
- Subarachnoid hemorrhage (bleeding in the area between the brain and the tissues that cover it)
- Inherited genetic abnormalities
In many cases, the cause of NPH is unknown.
How is normal pressure hydrocephalus diagnosed?
Tests used to diagnose NPH include:
- Physical and neurological exams
- Imaging tests, such as a CT scan or an MRI scan
- Tests to collect and evaluate your CSF, such as a lumbar puncture
- Impaired bladder control that ranges from frequent and urgent urination to complete loss of bladder control (urinary incontinence).
- Gait disturbances that range from mild imbalance to the inability to stand or walk.
- Mild dementia which is characterized by disorientation, confusion, apathy, loss of interest in daily activities, decreased attention span, mental slowing, anxiety, difficulty handling routine tasks, and frequent memory loss.
Because these symptoms are associated with a number of conditions that affect people over 60 years old, NPH is often underdiagnosed or misdiagnosed.
These symptoms do not always occur at the same time and can vary in severity.
Contact a medical professional if you are experiencing any of these symptoms.
NPH can be treated with a device called a shunt, which transports excess CSF away from the brain to another part of the body where it can be absorbed. A shunt operation is not a cure for NPH, as it does not treat the underlying cause, but the device remains in place indefinitely and can relieve symptoms.
Another operation that is used to treat NPH is an endoscopic third ventriculostomy. In this procedure, an endoscope is inserted into the brain to create a small hole in the floor of ventricles, allowing CSF to drain.
At Barrow Neurological Institute at Dignity Health St. Joseph’s Hospital and Medical Center, our team of normal pressure hydrocephalus experts will review your medical records, medical imaging, and other diagnostic tools to arrive at a concrete diagnosis and create a treatment plan that meets your specific needs.
- Date of last review: November 28, 2016