Diagnosing Normal Pressure Hydrocephalus
The symptoms of normal pressure hydrocephalus (NPH) are similar to some of the symptoms associated with a number of medical conditions, including dementia, Alzheimer’s disease, multiple sclerosis, and some movement disorders, such as Parkinson’s disease. Therefore, it is important to have a doctor evaluate you if you are 60 years old or older and you have all three of the following NPH symptoms at the same time.
- Trouble walking, standing, or balancing (gait)
- Trouble remembering things or identifying familiar objects (cognition)
- Trouble controlling your bladder (urinary incontinence)
If your primary-care doctor thinks you might have NPH, he or she will refer you to a neurologist or neurosurgeon with special training and experience in NPH. This doctor is part of a team of specialists who will conduct a two-part evaluation. The evaluation is designed specifically to determine if you have NPH.
Part 1: Initial Visit and Testing
During your first visit, the doctor talks with you about your medical history, and conducts a thorough physical exam. The doctor also may order a CT or MRI, and sometimes a special MRI to look at the volume of cerebrospinal fluid (CSF) and how it flows through your brain.
If the results of this initial evaluation suggest you might have NPH, the NPH team will perform a series of tests to see how well you can do certain tasks. The results of these tests are your baseline or starting point.
Step 1 - Gait and Balance Testing
The NPH team uses these tests to evaluate how well you are able to walk and whether you have trouble balancing while standing. During these tests our specialists will take a video of you performing simple movements. The team measures and characterizes how well you are able to perform these tests and they record the results.
Step 2 - Cognitive Testing
The team will also test you on how well you can focus on completing a task, remember simple things and identify familiar objects. During this test the specialists will ask you a series of questions and will ask you to perform a few tasks involving language, information processing and memory. They also record these results.
Step 3 - Lumbar Puncture
A lumbar puncture (also called a spinal tap) is a procedure to remove a specific amount of spinal fluid. This procedure can be done in your doctor’s office or in the hospital. Your doctor will sterilize and numb the lower portion of your back (the lumbar region) before carefully inserting a needle into the spinal canal to remove the correct amount of fluid.
Because removing spinal fluid may improve some NPH symptoms, a lumbar puncture helps the doctor make the diagnosis. If you have NPH, removing some fluid may relieve some of the pressure on your brain and you may have some improvement in your symptoms.
Before you leave the clinic, we will schedule you for a return visit the next day for part two of the testing and evaluation.
Part 2: Follow-Up Testing and Evaluation
When you return to the clinic the next day, the NPH team will take a video of you performing the same gait and balance testing that you did on the first day. You will also repeat the cognitive testing. They will record the results of the tests.
The doctor will compare the new video with the video from the previous day, as well as the results of both cognitive tests, to see if the lumbar puncture improved your symptoms.
Improvement: If your symptoms improved after draining the small amount of fluid, the doctor will talk with you about treatment, which includes inserting a small tube in your brain to help drain the fluid.
No improvement: If the results show no improvement, but the team’s evaluation and the MRI images suggest NPH, the doctor may talk with you about admitting you to the hospital for three to four days for more testing. While you are in the hospital, the doctor will insert a lumbar drain to allow a larger amount of spinal fluid to drain. You will have daily gait and cognitive testing. If your symptoms improve after draining more fluid, the doctor will talk with you about treatment. No improvement after testing in the hospital confirms you do not have NPH.
Adult Hydrocephalus Program751 N.E. Blakely Dr.
Issaquah, WA 98029
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