Exams and Tests

The symptoms of NPH can occur in Alzheimer disease and Parkinson disease. However, the combination of dementia-like symptoms, walking problems, and urinary problems should alert your health care provider to the possibility of NPH. Making the distinction is very important because the treatments for these conditions are quite different. Tests are available that can confirm the diagnosis. At any point in this process, your health care provider may refer you to a specialist in brain disorders (neurologist or neurosurgeon) to complete the evaluation and begin treatment.

The evaluation begins with a medical interview. The interviewer will ask you questions about your symptoms and when they started, your medical and mental problems now and in the past, your family's medical problems, medications you have taken now and in the past, your work and travel experiences, and your habits and lifestyle. This is followed by a detailed physical examination to document your condition and rule out other disorders that might cause similar symptoms. The examination will probably include tests of your mental status, such as answering questions and following simple directions. Neuropsychological testing may be performed to document your dementia symptoms.

Neuropsychological testing

Neuropsychological testing is the most accurate method of pinpointing and documenting a person's cognitive problems and strengths.

• This can help give a more accurate diagnosis of the problems and thus can help in treatment planning.
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• The testing involves answering questions and performing tasks that have been carefully prepared for this purpose. The test is given by a neurologist, psychologist, or other specially trained professional.
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• It addresses the individual's appearance, mood, anxiety level, and experience of delusions or hallucinations.
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• It assesses cognitive abilities such as memory, attention, orientation to time and place, use of language, and abilities to carry out various tasks and follow instructions.
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• Reasoning, abstract thinking, and problem solving also are tested.

Lab tests

There is no lab test that confirms the diagnosis of NPH. Any lab tests that are done are probably being done to rule out conditions that might cause similar symptoms.

Imaging studies

• CT scan of the head: This scan is similar to an x-ray but gives a more detailed, 3-dimensional picture of the brain. It cannot confirm a diagnosis of NPH, but it can show ventricular enlargement or other changes that suggest NPH. These findings alone are not sufficient for diagnosis. This scan is safe and painless.
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• MRI of the head: This scan uses radio signals and a strong magnet to create a detailed picture of the brain. It is safe and painless, like CT scan, but takes longer (about 1 hour). It also cannot confirm a diagnosis of NPH.
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• Cisternography: This test is much more involved than CT scan or MRI and is not widely used. It highlights absorption of the CSF.

Other tests

Lumbar puncture (spinal tap): This procedure involves removal of CSF from the area around the spinal cord in the lower back.

• The CSF pressure is measured, and the fluid that is removed is analyzed for abnormalities that might give a clue as to the problem.
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• Usually, more fluid is removed than is necessary for these tests. The idea behind this is that removal of a large volume of CSF helps relieve symptoms. (This is checked by comparing examination results before and after.)
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• This effect usually is only temporary. However, improvement of symptoms with lumbar puncture is commonly interpreted as meaning that a surgical shunt would be helpful in that person.