From the Research
The primary treatment for normal pressure hydrocephalus (NPH) is surgical placement of a ventriculoperitoneal (VP) shunt, as it has been shown to improve symptoms in most patients, with a significant improvement in gait, balance, and continence domains, as demonstrated in a multicenter prospective observational study 1. This procedure involves inserting a catheter into the brain's ventricles to drain excess cerebrospinal fluid (CSF) into the peritoneal cavity of the abdomen, where it can be absorbed by the body. The shunt system includes a one-way valve that regulates the flow of CSF and prevents backflow. Some key points to consider when treating NPH include:
- Before proceeding with shunt placement, patients typically undergo diagnostic tests including a lumbar puncture with large-volume CSF removal (30-50 mL) to predict response to shunting.
- Approximately 60-80% of properly selected patients show improvement after shunt surgery, particularly in gait disturbance, which tends to respond better than cognitive or urinary symptoms.
- Improvement is usually seen within days to weeks after surgery.
- Potential complications include infection, bleeding, shunt malfunction, and overdrainage, so regular follow-up with a neurosurgeon is essential.
- The procedure is effective because NPH results from impaired CSF absorption leading to ventricular enlargement and compression of brain tissue, and shunting directly addresses this underlying pathophysiology by providing an alternative drainage pathway for the excess fluid. It's also important to note that setting the valve opening pressure close to the lumbar puncture opening pressure can decrease overdrainage, as shown in a study published in 2020 2. Additionally, a study from 2012 found that lumboperitoneal shunts with horizontal-vertical valves can be a safe and effective alternative to ventriculoperitoneal shunting for iNPH, resulting in significant symptomatic improvement with a low risk of overdrainage 3. However, the most recent and highest quality study, published in 2022, supports the use of ventriculoperitoneal shunts as the primary treatment for NPH 1.