Surgery Can Help ‘water On The Brain’
Q: What can be done for normal pressure hydrocephalus? My dad was diagnosed with this condition six months ago after developing severe gait problems, urinary urgency and memory issues. He has a few other physical issues but is otherwise healthy. A: I’m glad your father’s doctor was able to pinpoint the source of his symptoms. Because normal pressure hydrocephalus (NPH) is a rare condition with a gradual onset of symptoms, it can be difficult to diagnose. The annual incidence is between 1.19 and 3.4 per 100,000 people. This form of hydrocephalus, or “water on the brain,” can occur after a head trauma, stroke or brain tumor, but in some cases, the cause is unknown. To understand the condition takes an understanding of the fluid that bathes the entire brain and that flows through its ventricles, or cavities. This fluid, called cerebrospinal fluid, is produced by the lateral ventricles of the brain and is eventually reabsorbed into the body through veins within the brain. If the body has difficulty reabsorbing the fluid, the fluid increases within the ventricles, putting pressure on the brain itself. This pressure damages the nerves and nerve connections within the brain. Initial symptoms include difficulty walking, as if a person’s feet are glued to the floor, and with the feet outwardly rotated. Patients also have difficulty turning and can lose stability and fall. People with the condition also have concentration problems, slowed mental abilities and a lack of concern for their disability. Lastly, they have urinary urgency, which can lead to incontinence. Once you have a diagnosis, however, you can move to treatment, which consists of decreasing the level of cerebrospinal fluid within the skull. This is done through a ventriculoperitoneal (VP) shunt. After drilling a small hole in the skull, a neurosurgeon places a catheter into the lateral ventricle in the brain. That catheter is attached to a valve behind the ear. From the valve, another catheter is guided down the neck and into either the chest or abdomen. When the pressure builds in the ventricle, the valve opens, draining the fluid from the brain into the chest or abdomen. The fluid is reabsorbed by the body. The effectiveness of shunts varies widely, studies suggest. The greatest patient improvements seem to be in the ability to get up out of a chair and walk. Memory and reaction time also can improve after shunting, as can urinary symptoms. However, if memory deficits are to the point of moderate to severe dementia, a shunt may not help that aspect. One important thing to note is that the longer the patient has symptoms, the less likely a shunt will provide benefit. ASK THE DOCTORS is written by Robert Ashley, M.D., Eve Glazier, M.D., and Elizabeth Ko, M.D. Send questions to askthedoctors@ mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.