From the Research
The current treatment recommendation for Normal Pressure Hydrocephalus (NPH) is surgical placement of a ventriculoperitoneal (VP) shunt, as evidenced by the most recent and highest quality study 1. This procedure involves implanting a catheter system that diverts excess cerebrospinal fluid (CSF) from the brain's ventricles to the peritoneal cavity where it can be absorbed. Patient selection is critical, with the best candidates being those who demonstrate the classic triad of symptoms (gait disturbance, urinary incontinence, and cognitive decline) and show improvement after a diagnostic lumbar tap test or extended lumbar drainage, as supported by 1 and 2.
Key Considerations
- The procedure is typically performed under general anesthesia and requires regular follow-up to monitor shunt function.
- Programmable shunts are often preferred as they allow for non-invasive pressure adjustments post-surgery.
- While medication therapy alone is not effective for NPH, patients should be counseled that symptom improvement varies, with gait disturbance typically responding best to shunting (60-90% improvement), followed by urinary symptoms (50-70%), and cognitive function (40-60%) 3, 1.
- Early intervention generally yields better outcomes, as longstanding symptoms may become irreversible.
- Complications can include infection, over-drainage, subdural hematoma, and shunt malfunction, occurring in approximately 30% of cases, so patients require vigilant monitoring 3, 1.
Patient Selection and Evaluation
- A standardized assessment of gait, balance, and cognition before and after temporary cerebrospinal fluid diversion can identify patients with NPH likely to benefit from VPS placement, with a low complication rate 1.
- The tap test has a high positive predictive value as a predictor of therapeutic response, but a negative test does not exclude the possibility of treatment 2.
- Recent studies have led to improved recognition of overlapping diseases such as Alzheimer pathology, which co-occurs in about 30% of NPH cases, highlighting the importance of a comprehensive diagnostic approach 4.