Research & Discovery

Q&A: What Is Normal Pressure Hydrocephalus, the Condition Billy Joel Just Revealed?

Musician Billy Joel recently canceled his concert tour, announcing he will undergo physical therapy for a condition called normal pressure hydrocephalus that is affecting his hearing, vision and balance.

UVA Health’s Neurology Department recently opened a clinic to treat the condition, so UVA Today asked the clinic’s Dr. Michael Catalino about the condition, who is vulnerable and how it is treated.

Dr. Michael Catalino is a neurosurgical oncologist. He specializes in the surgical treatment of brain and spine tumors. (Contributed photo)

Q. Exactly what is the condition?

A. Normal pressure hydrocephalus is a disorder that occurs when the neurons in the brain are stretched by expansion of the ventricles. The ventricles are fluid spaces in the brain that normally circulate fluid and other metabolites throughout the central nervous system. These fluid spaces can enlarge and stretch the major neuronal networks in the brain. The effects on the patient include gait disturbance, cognitive impairment and urinary incontinence.

Q. What causes it?

A. Nobody really knows exactly what causes it. Mostly, what we see with the expansion of the ventricles is probably a secondary issue. Sometimes trauma, infection or subarachnoid hemorrhage can cause it, but the most common situation we encounter is what’s called idiopathic normal pressure hydrocephalus. These are patients who don’t have those aforementioned underlying causes.

The other theories involve a pressure or compliance-based cause. Each heartbeat translates pressure into the brain. When you’re young, your brain is healthy and it’s able to withstand that pressure … but over time … the more compliant brain stretches out a little bit with each pulsation, and this causes enlargement of the ventricles and stretching of neuronal networks.

Q. Who is most vulnerable?

A. Most everybody in the elder years of their life, around the ages of 60 or 70, starts becoming at-risk. There’s a slight male predominance, and some studies suggest patients with hypertension, diabetes or cardiovascular diseases might be affected more often.

Q. Can you tell us about the new clinic?

A. Dr. Alissa Higinbotham and Dr. Binit Shah run the clinic with me. We screen patients who come in with these other disorders. It usually involves the clinical diagnosis, which is based on the neurological exam and the history, and then imaging studies of the brain to look for disproportionate … expansion of the ventricles relative to the degree of cerebral atrophy.

Q. What happens next?

A. The real gold standard test for understanding whether or not this is normal pressure hydrocephalus requires what’s called a high-volume lumbar puncture, where we drain cerebral spinal fluid from the back. This lumbar puncture is accompanied by a pre-test and a post-test evaluation by physical therapy, where they do a number of detailed tests on the patient’s mobility to understand whether or not there’s an immediate difference after the spinal tap. It really helps us understand if we do provide treatment, the magnitude of benefit the patient will receive.

Q. Is the condition fatal?

A. Normal pressure hydrocephalus itself is usually not fatal in the sense that it will cause such severe pressure in the head – hence “normal” pressure – that a patient will die from the disease. However, the side effects of the disease, such as gait disturbance, memory issues, the urinary incontinence, can lead to secondary causes of death, such as a head injury from a fall or spinal cord injury, urinary tract infections or other causes that could ultimately be detrimental to the patient’s life.

Q. How is it treated?

A. The most common treatment is a ventriculo-peritoneal shunt … a catheter that goes into the fluid space and then drains through a tube under the skin into the abdomen, which then reabsorbs the fluid and puts it back into circulation. It diverts the fluid away from the brain to help relax those neurons.

The other treatment is a little bit more innovative but rarely used for typical idiopathic normal pressure hydrocephalus. It’s called an endoscopic third ventriculostomy and involves driving a small camera into the brain and making a tiny hole in the very bottom of the third ventricle, which is essentially an area where there are no functional neurons, to help divert the fluid around the ventricles. I usually reserve that treatment for patients who have some evidence of obstruction, like a tumor, cyst, or adhesion. It is a minimally invasive way to divert fluid away from the blockage.