To help confirm a diagnosis of normal pressure hydrocephalus (NPH), in some cases prolonged drainage of cerebrospinal fluid may be necessary. This is performed by inserting a lumbar drain to drain cerebrospinal fluid (CSF).
Prolonged drainage of CSF must be performed in the hospital, requiring close monitoring of the patient. Daily cognitive and ambulatory assessments are conducted to evaluate for potential benefit to the patient.
Much like a lumbar puncture, this procedure is well tolerated, but carries risks of infection, bleeding, over-drainage and nerve injury. Typically, patients stay in the hospital for about three of four days. The data collected by this test will help determine the benefit of a ventriculoperitoneal shunt.