What is normal pressure hydrocephalus (NPH)? All about the brain condition affecting Billy Joel

“Piano Man” singer Billy Joel, 76, said Friday that he is bowing out of his 2025 tour after being diagnosed with the brain condition normal pressure hydrocephalus (NPH).

Recent live performances “lead to problems with hearing, vision, and balance,” Joel said on Instagram.

He was advised by his doctor to refrain from performing while he undergoes treatment and recovery.

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The “New York State of Mind” performer postponed several tour dates in March due to a “medical condition” that forced him to “undergo physical therapy under the supervision of his doctors” following an onstage fall in February.

“I’m sincerely sorry to disappoint our audience, and thank you for understanding,” Joel said Friday in response to the latest round of cancellations.

What is NPH?

Hydrocephalus occurs when cerebrospinal fluid (CSF) builds up in the brain, disrupting cognitive functioning.

CSF provides nutrients to and removes waste products from the brain while cushioning it and the spinal cord from force.

Typically, adults have 5 fluid ounces of CSF, with the body constantly producing, circulating and reabsorbing the fluid to keep that level constant.

But when the body fails to circulate or reabsorb CSF correctly, it can accumulate.

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In NPH, this buildup is usually gradual enough that the pressure inside the skull increases, but stays within normal range. The fluid runs into the brain’s ventricles, which can hold some of the overflow.

“NPH is a type of hydrocephalus that is seen typically in older people,” Dr. Matthew Potts, associate professor of neurological surgery, radiology and neurology at Northwestern University Feinberg School of Medicine, told The Post.

“The fluid builds up, and it doesn’t necessarily affect the pressure in the brain — hence the ‘normal pressure’ part — but it still affects the brain.”

If CSF keeps collecting, the brain begins to compress. If this compression lasts too long, permanent damage can occur.

NPH is most common in seniors, with the average age of diagnosis being 70.

NPH affects about 0.2% of people between the ages of 70 and 80 and about 6% of people over 80. It’s very rare in people under 65.

What are the symptoms?

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NPH symptoms begin gradually and worsen over the course of three to six months. The three primary symptoms are known as Hakim’s triad and include:

• Urinary incontinence
• Difficulty walking
• Cognitive difficulties, including memory issues and emotional changes

Between 50% and 75% of people with NPH exhibit the three symptoms at the same time.

“The three classic symptoms of NPH — cognitive/memory problems, issues with balance/gait and urinary incontinence — are very similar to a lot of other things that can happen in older adults,” Potts said.

“So, some people may be diagnosed with dementia even though it’s NPH. If it happens that it’s caused by NPH, we have a treatment for it.”

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What causes NPH?

There are two forms of NPH — primary (idiopathic) NPH and secondary NPH. Joel has not disclosed the form of NPH he has.

Primary NPH accounts for half of all cases and is attributed to age-related issues that compromise the body’s ability to make, circulate and reabsorb CSF.

Evidence suggests that NPH may be connected to degenerative brain conditions like Cleveland Clinic.

Secondary NPH is characterized by an underlying medical condition that affects the body’s ability to regulate CSF. These conditions include brain aneurysms and tumors, infections like encephalitis or meningitis, stroke and/or traumatic brain injuries.

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How is NPH diagnosed?

NPH is a worsening condition that affects cognition, meaning many people don’t know they have it. That makes early detection difficult and early treatment critical. 

Because of the overlap between symptoms of dementia and NPH, diagnosing NPH is challenging.

Doctors tend to eliminate other possibilities using a combination of methods, including spinal tap, physical and neurological examination and diagnostic imaging.

“There is not one test that says ‘Yes, this is NPH.’ For some patients, fluid will build up and a brain scan (CT scan or MRI) might show it, but that doesn’t mean it’s NPH,” Potts said.

“Ultimately, it comes down to do the symptoms really fit with the picture physicians see?”

How is NPH treated?

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Primary NPH is typically treated with surgery and the implementation of a shunt. One end of the shunt goes into the CSF, while the other end usually goes to the abdomen to drain the excess fluid.

Neurosurgeons often do a test simulating what would happen if they drained the fluid, Potts said.

“We place a needle into the lower back to drain the fluid (called a lumbar puncture or spinal tap), which acts as a tiny temporary drain that helps the fluid slowly exit the body through their skin over a few days to simulate if they had a shunt,” he added.

“We ask: Do they get better? If over a few days their balance and gait improve, we say, if we place a shunt, you’ll probably get better. If not, we say it might not be NPH.”

The type and efficacy of secondary NPH treatment depend on the underlying cause.

NPH prognosis

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Unlike other dementia-like conditions, NPH is often reversible, with a positive prognosis tied to early diagnosis and treatment. 

The longer NPH goes undiagnosed, the more likely the increase in pressure will result in severe or permanent brain damage. 

Mobility issues, cognitive difficulties and urinary incontinence are likely to improve with treatment.