CEREBROSPINAL-FLUID CONDUCTANCE AND COMPLIANCE OF THE CRANIOSPINAL SPACE IN NORMAL-PRESSURE HYDROCEPHALUS - COMPARISON BETWEEN 2 METHODS FOR MEASURING CONDUCTANCE TO OUTFLOW

Conductance to outflow of cerebrospinal fluid CSF was measured by both a lumboventricular perfusion and a bolus injection method in 24 patients with normal-pressure hydrocephalus. One purpose was to investigate whether the less time-consuming technique of bolus, injection gave results comparable to the results obtained by the lumboventricular perfusion technique. There was a poor correlation between the results obtained by the 2 measurements of conductance to outflow of CSF. The bolus-injection technique cannot substitute for the lumboventricular perfusion test. Compliance of the CSF space was measured by the bolus injection. The presence of B-waves, recorded from long-term intraventricular pressure monitoring, could be correlated to the sum of conductance to outlfow and compliance. The correlation offers a possible explanation of the nature of B-waves.