Am Fam Physician. 2004;70(6):1085-1086
What is normal pressure hydrocephalus?
Normal pressure hydrocephalus (say: hi-drosef-uh-lus; or NPH for short) is a rare, but sometimes treatable, cause of dementia. It mainly affects people older than 60. It does not run in families. Sometimes it happens after a brain infection, such as meningitis. Other times, it happens after a brain injury. Often, it happens for no reason at all.
What happens if I have NPH?
With NPH, the fluid inside your brain doesn’t drain as it should. Fluid usually is formed and stored inside special spaces in your brain. These spaces are called ventricles. Usually, there is a balance between the amount of fluid made and the amount of fluid taken away. When the fluid doesn’t drain right, the ventricles get bigger and can press on nearby brain tissue. This pushing can change the shape of the brain a little bit. This change in shape can make you think slower, have trouble walking, and perhaps lose control of your bladder.
What are some signs to look for?
You may have trouble walking.
You may fall down and need help to get up.
You may pause before you start walking.
Your feet may feel stuck to the floor.
You may shuffle, or walk with your feet spread wide apart.
You may pause for a while before you start to speak.
You may take a long time to answer questions.
It may take a while to think about, or understand, what people say to you.
You may lose control of your bladder.
What do I do if I think I have NPH?
If you or members of your family notice these signs, you should see your doctor. Your doctor will want to talk to you, and also may want to speak with the friends or family members you bring along. Your doctor will watch you walk. Your doctor will note how long it takes you to answer questions. Your doctor will want to know if you are sometimes unable to hold your urine and how often this happens.
Once your doctor has all this information, he or she may want to take a picture of your brain. Sometimes a lumbar puncture (also known as a spinal tap) may help your doctor figure out if you have NPH.
During a spinal tap, your doctor will remove some fluid from your back. After the spinal tap, your doctor will check to see how smoothly you walk or if you answer questions faster. Your doctor also will want to know if you still have a hard time making it to the bathroom in time to urinate.
How is NPH treated?
If you have NPH, your symptoms may get better if a surgeon places a shunt. A shunt is a tube that is put in, starting inside one of your brain ventricles and is then tunneled under your scalp and beneath the skin along your neck and chest. The tail end of the tube is put inside the space around your stomach. Extra fluid inside your brain can then drain from the brain into your abdomen. Fluid runs only one way because there is a valve in the tube.
Will I get better?
With the fluid draining out of your brain, fluid will not build up and the ventricles may not grow so large. Then the nerve fibers may not be pushed out of shape and messages may reach down to your feet and bladder like they used to. The decrease in brain fluid may help you walk better, think more clearly, and urinate only when you want to. The decrease in brain fluid may help you understand what people say. You also may think of answers more quickly.