Normal pressure hydrocephalus (NPH) is most commonly treated with a surgical placement of a shunt system, which drains cerebrospinal fluid (CSF) into another area of the body (ventriculoperitoneal, lumboperitoneal, ventriculoatrial shunting) where the body can absorb it.
Surgical interventions performed in the early stages of the disease seem to have the greatest benefit. As with any surgical procedure, a risk-to-benefit ratio should be carefully considered before undergoing a CSF shunting procedure. Such factors as advanced age, comorbidity, immune incompetence and functional and coagulation status should be taken into account. It is advised to stop systemic anticoagulation perioperatively, thus the expected improvement from shunting should justify the added risk. A ventriculoparitoneal shunting procedure may not always prevent further progression of the disease, but even a temporary improvement may make a significant difference.
Overall, improvement rates range from 30% to 96% in the literature (Klinge et al., Neurosurgery, 2005). This wide variation further supports the importance of correctly identifying patients who most likely would benefit from shunting. Patient selection is usually based on clinical and diagnostic findings, although sometimes additional adjunctive testing is necessary to confirm the diagnosis. Some of these tests may be beneficial in predicting a positive response to the CSF shunting procedure, but cannot indicate its sustainability over time.
Based on the current literature, the best and more consistent results are obtained in patients with the typical clinical triad in addition to the imaging criteria with improvement rates ranging from 61% to 77% (Black, J Neurosurg 1980; Benzel et al., Neurosurgery, 1990). In a long-term study that compared clinical outcomes, the shunt-treated patients had a lower need for care than the non-shunted patients (Savolainen, et al, Acta Neurochir (Wien), 2002). Early identification and selection of good candidates for the shunting procedure can potentially reverse or relieve symptoms and provide these patients with an improved quality of life.