IDIOPATHIC NORMAL-PRESSURE HYDROCEPHALUS - ANALYSIS OF FACTORS RELATED TO CEREBROSPINAL-FLUID DYNAMICS DETERMINING FUNCTIONAL PROGNOSIS

This investigation has been undertaken to analyze the findings with bo th the cerebrospinal fluid (CSF) pressure (Pcsf) and CSF pulse pressur e (PP) in order to predict the outcome of patients with the syndrome o f idiopathic normal pressure hydrocephalus (NPH). Accordingly, a prosp ective clinical study was planned in which two groups of patients with NPH, having analogous prevalence of several matched clinical and radi ological parameters, were separated on the basis of their positive or negative response to shunting. Both the resting Pcsf and CSF PP profil es were compared in these two groups, and between them and normal cont rols. CSF PP amplitude and CSF PP latency correlated directly in condi tions associated with either normal or high compliance (controls and p atients with Alzheimer-like disorders), whereas this correlation was i nverse in states of low compliance (NPH). On the other hand, shunt-res ponders showed a resting Pcsf significantly higher than both nonrespon ders and controls. The following conclusions were obtained: 1) CSF PP is a high-amplitude and relative low-latency wave in NPH when compared with controls; 2) CSF PP amplitude and latency correlate directly in normal subjects and in those with primary cerebral atrophy; 3) a non-r eversible stage of NPH could be conceived in contradistinction to the reversible one, in both of which an inverse correlation between the am plitude and the latency takes place, the main difference between them being the resting Pcsf, which is significantly lower in the former tha n in the latter, depending on the degree of atrophic changes developed .