24-05-2025
All you need to know about: Normal Pressure Hydrocephalus
Music legend Billy Joel made headlines on Saturday (May 24) after announcing the cancellation of several upcoming concerts due to a diagnosis of Normal Pressure Hydrocephalus (NPH). The news left many fans wondering what exactly this condition is, and why it can be so disruptive.
NPH is a rare but potentially treatable neurological condition that mainly affects older adults. It is marked by a slow buildup of cerebrospinal fluid in the brain's ventricles, the fluid-filled spaces that help cushion the brain. Despite the increased volume of fluid, the pressure inside the skull remains normal, hence the name. But the effects can be serious. Problems with walking, memory, and bladder control are common, and the symptoms can easily be mistaken for other age-related disorders like Alzheimer's or Parkinson's disease.
Here's what you need to know about NPH, how it develops, how it's diagnosed, and why early treatment can make all the difference.
What is Normal Pressure Hydrocephalus?
NPH is a type of hydrocephalus, a condition where excess cerebrospinal fluid (CSF) builds up in the brain's ventricles, causing them to enlarge and put pressure on surrounding brain tissue. This fluid normally cushions the brain and spinal cord, but when it doesn't drain or absorb properly, it can lead to brain damage. While NPH typically affects older adults, congenital hydrocephalus is present at birth and is usually caused by genetic factors or developmental disorders and acquired hydrocephalus, on the other hand, develops later in life due to factors like brain injury, infection, tumour, bleeding, or complications from surgery.
What are the symptoms of NPH?
According to the U.S. National Institute of Neurological Disorders and Stroke (NINDS), people with NPH typically develop a trio of symptoms that worsen over time. These include trouble walking, memory and thinking difficulties, and problems with bladder control. Walking may become unsteady; patients may shuffle, take short steps, or struggle to turn.
Cognitive symptoms often include forgetfulness, slowed thinking, or a lack of attention and interest in daily activities. In some cases, the person may become withdrawn or seem confused.
Bladder symptoms, such as frequent urination or incontinence, may also appear and can be mistaken for unrelated issues. The NINDS says the symptoms of NPH can become severe and even life-threatening if left untreated.
A 2019 review published in the journal Dementia and Neuropsychologia notes that while both NPH and Alzheimer's disease cause memory problems, the underlying brain changes are different. In NPH, the cognitive decline is mainly due to issues in parts of the brain responsible for processing speed and decision-making, leading to what's called a 'subcortical' type of dementia. Alzheimer's, on the other hand, is marked by damage to the brain's cortex and is often associated with language loss, disorientation, and difficulty recognising familiar objects.
What are the types of NPH?
There are two known types of NPH. The first is called idiopathic NPH, which means it appears without any known cause. This form primarily affects older adults and is the most commonly diagnosed type. The second type is known as secondary NPH, which can occur after a brain injury, stroke, infection, hemorrhage, or even as a complication following brain surgery.
Despite these differences, both types involve the same underlying problem, which is disruption in the brain's ability to circulate and absorb cerebrospinal fluid properly. According to the United States' National Center for Biotechnology Information, both are also considered 'communicating' forms of hydrocephalus, meaning that while CSF can still flow between the ventricles, its absorption into the bloodstream is impaired.
According to the NCBI, this imbalance in fluid absorption is central to the development of NPH. Diagnosing NPH is often challenging because its symptoms develop slowly and can easily be mistaken for other neurological disorders.
Who can get NPH?
Although NPH is more common in older adults, it can occur in people of all ages, particularly in its secondary form. What makes it especially important to identify is that, unlike many other forms of dementia or neurological disease, NPH can often be improved or reversed with treatment. Early intervention offers the best chance of recovery, studies suggest. Without it, symptoms may gradually worsen and significantly reduce a person's quality of life.
How is NPH diagnosed?
According to the U.K.'s National Health Service (NHS), a proper diagnosis involves a combination of physical and cognitive evaluations along with brain imaging. Doctors often assess how a person walks, their memory and reasoning abilities, and their ability to control their bladder. Brain scans, such as a CT or MRI, are used to detect enlarged ventricles that indicate a buildup of fluid. In some cases, further testing is needed to determine if a person might benefit from surgery.
This may involve a lumbar puncture, where a sample of cerebrospinal fluid is drawn from the lower back. If the removal of fluid leads to noticeable improvement in symptoms, surgery may be recommended. Other tests, like lumbar drainage over a few days or a lumbar infusion test, may also help determine how well the body manages CSF and whether intervention will help.
How is NPH treated?
The main treatment for NPH is the surgical insertion of a shunt — a small tube that drains excess fluid from the brain to another part of the body, usually the abdomen, where it can be safely absorbed.
This procedure can relieve pressure on the brain and ease symptoms, especially if done early. However, shunts can sometimes become blocked, infected, or fail, which means that patients may need further surgeries over time. According to NINDS, researchers are currently studying new shunt designs, including smart shunts that can monitor pressure and adjust drainage automatically, potentially reducing the need for repeat surgeries. Studies are also underway to see whether electrostimulation of neck muscles can improve CSF flow and reduce pressure inside the brain.
