Does compliance predict ventricular reduction after shunting for normal pressure hydrocephalus.

Ventricular reduction after shunting for normal pressure hydrocephalus (NPH) was classified on the basis of magnitude and rate of reduction in 35 adult patients. Brain compliance and resistance to outflow of cerebrospinal fluid (RCSF) were determined before shunting. Rapid and marked ventricular reduction (n = 11) was associated with a significantly lower compliance than slow and moderate to marked (n = 16) or minimal to mild (n = 8) reduction. Otherwise ventricular size before as well as after shunting did not correlate with compliance or RCSF. It is concluded that both rate and magnitude of ventricular reduction after shunting for NPH vary widely. Reduced compliance seems to be the best predictor of rapid and marked reduction.