How is normal pressure hydrocephalus (NPH) diagnosed?
Diagnosis begins with a careful review of symptoms and medical history. medical interview and a physical exam. Other tests include:
- Imaging tests. A CT scan or MRI of the head is done to look for enlarged ventricles in the brain.
- Cerebrospinal fluid tests. These tests include a spinal tap and external lumbar drainage. During a spinal tap, a small sample of cerebrospinal fluid is removed and the patient is assessed to see if the symptoms improve. During external lumbar drainage, cerebrospinal fluid is removed through a special catheter (tube) over a 36-hour period to further see if symptoms improve dramatically and to test the potential benefit of implanting a shunt (see treatment).
- Gait analysis (walking). This is a timed walk test. The patient is watched as he or she walks 10 meters (about 30 feet).
- Neuropsychological testing. This involves a series of assessments to determine if there is a loss of brain function (including memory, concentration and problem-solving) due to NPH.